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1. OVERVIEW OF THE BEDROCK GEOCHEMISTRY AND MINERALOGY OBSERVED BY SUPERCAM DURING PERSEVERANCE'S DELTA FRONT CAMPAIGN

Author: Dehouck, Erwin, Forni, Olivier, Quantin-Nataf, Cathy, Beck, Pierre, Mangold, Nicolas, Royer, Clément, Clavé, Elise, Beyssac, Olivier, Johnson, Jeffrey, Mandon, Lucia, Poulet, François, Le Mouélic, Stéphane, Caravaca, Gwénaël, Kalucha, Hemani, Gibbons, Erin, Dromart, Gilles, Gasda, Patrick, Meslin, Pierre-Yves, Schroeder, Susanne, Udry, Arya, Anderson, Ryan B., Clegg, Samuel, Cousin, Agnès, Gabriel, Travis, Lasue, Jérémie, Fouchet, Thierry, Pilleri, Paolo, Pilorget, Cédric, Hurowitz, Joel, Núñez, Jorge, Williams, Amy, Russell, Patrick, Simon, Justin I., Maurice, Sylvestre, Wiens, Roger, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), McGill University = Université McGill [Montréal, Canada], Los Alamos National Laboratory (LANL), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), University of Nevada [Las Vegas] (WGU Nevada), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), United States Geological Survey (USGS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), NASA Johnson Space Center (JSC), NASA, and Lunar and Planetary Institute
Subjects: jezero crater, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, mars, delta front, geochemistry
Abstract: International audience; In February 2021, the Perseverance rover landed in Jezero crater, Mars. The crater floor was found to be composed of lava flows and cumulate rocks [1-5]. These magmatic rocks appear to have undergone some limited aqueous alteration; however, it is not clear whether this alteration is related to the lacustrine phase of the crater [1,3,6,7].After completing its exploration of the crater floor, Perseverance reached the foot of the Jezero western fan in late April 2022 (sol ~422). Long-distance images acquired earlier in the mission had already confirmed the deltaic nature of the fan [8], which had long been suspected from orbital observations [9,10]. Between April and December 2022, Perseverance investigated the basal layers of the delta at two locations named Hawksbill Gap and Cape Nukshak, which are ~400 m apart [11]. Here, we present an overview of the geo-chemistry and mineralogy of the delta rocks as observed by SuperCam, and show that these rocks record a diver-sity of past aqueous alteration environments.
Published: 2023

2. Comparison of dust between Gale and Jezero

Author: Lasue, J., Meslin, P. Y., Cousin, A., Forni, O., Anderson, R., Beck, P., Clegg, S. M., Dehouck, E., Frydenvang, J., Gasda, P., Olivier Gasnault, Hausrath, E., Le Mouélic, S., Maurice, S., Pilleri, P., William Rapin, Wiens, R. C., Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Los Alamos National Laboratory (LANL), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH), University of Nevada [Las Vegas] (WGU Nevada), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Lunar and Planetary Institute, and Gasnault, Olivier
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology
Abstract: International audience
Published: 2022

3. Overview of the Morphology and Chemistry of Diagenetic Features in the Clay-Rich Glen Torridon Unit of Gale Crater, Mars

Author: Patrick J. Gasda, Jade Comellas, Ari Essunfeld, Debarati Das, Alexander B. Bryk, Erwin Dehouck, Susanne P. Schwenzer, Laura Crossey, Kenneth Herkenhoff, Jeffrey R. Johnson, Horton Newsom, Nina L. Lanza, William Rapin, Walter Goetz, Pierre‐Yves Meslin, John C. Bridges, Ryan Anderson, Gael David, Stuart M. R. Turner, Michael T. Thorpe, Linda Kah, Jens Frydenvang, Rachel Kronyak, Gwénaël Caravaca, Ann Ollila, Stéphane Le Mouélic, Matthew Nellessen, Megan Hoffman, Deirdra Fey, Anges Cousin, Roger C. Wiens, Samuel M. Clegg, Sylvestre Maurice, Olivier Gasnault, Dorothea Delapp, Adriana Reyes‐Newell, Los Alamos National Laboratory (LANL), McGill University = Université McGill [Montréal, Canada], University of California [Berkeley] (UC Berkeley), University of California (UC), The Open University [Milton Keynes] (OU), The University of New Mexico [Albuquerque], US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, University of Leicester, Texas State University, NASA Johnson Space Center (JSC), NASA, The University of Tennessee [Knoxville], Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Malin Space Science Systems (MSSS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Solar System Research (MPS), Laboratoire de Planétologie et Géosciences - Angers (LPG-ANGERS), and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST)
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Geophysics, ChemCam, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Mars Science Laboratory, Glen Torridon, Gale crater, diagenesis, Gale Crater, Diagenesis
Abstract: International audience; The clay-rich Glen Torridon region of Gale crater, Mars, was explored between sols 2300 and 3007. Here, we analyzed the diagenetic features observed by Curiosity, including veins, cements, nodules, and nodular bedrock, using the ChemCam, Mastcam, and Mars Hand Lens Imager instruments. We discovered many diagenetic features in Glen Torridon, including dark-toned iron- and manganese-rich veins, magnesium- and fluorine-rich linear features, Ca-sulfate cemented bedrock, manganese-rich nodules, and iron-rich strata. We have characterized the chemistry and morphology of these features, which are most widespread in the higher stratigraphic members in Glen Torridon, and exhibit a wide range of chemistries. These discoveries are strong evidence for multiple generations of fluids from multiple chemical endmembers that likely underwent redox reactions to form some of these features. In a few cases, we may be able to use mineralogy and chemistry to constrain formation conditions of the diagenetic features. For example, the dark-toned veins likely formed in warmer, highly alkaline, and highly reducing conditions, while manganese-rich nodules likely formed in oxidizing and circumneutral conditions. We also hypothesize that an initial enrichment of soluble elements, including fluorine, occurred during hydrothermal alteration early in Gale crater history to account for elemental enrichment in nodules and veins. The presence of redox-active elements, including Fe and Mn, and elements required for life, including P and S, in these fluids is strong evidence for habitability of Gale crater groundwater. Hydrothermal alteration also has interesting implications for prebiotic chemistry during the earliest stages of the crater’s evolution and early Mars.
Published: 2022
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4. Comparing SuperCam first shots at Jezero with ChemCam eolian dust analysis at Gale

Author: Jeremie Lasue, Pierre-Yves Meslin, Agnes Cousin, Olivier Forni, Ryan Anderson, Erwin Dehouck, Jens Frydenvang, Olivier Gasnault, William Rapin, Paolo Pilleri, Sam Clegg, Roger Wiens, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH), and Los Alamos National Laboratory (LANL)
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology
Abstract: Context:On February 18th 2021, the NASA Perseverance rover landed at Jezero crater, Mars, a 50 km Noachian-aged open-basin lake system located on the western side of the Isidis impact structure. The bottom of the crater indicates the presence of a fluvial delta with associated inlet and outlet valleys and infrared observations from orbit have detected the presence of carbonate, mafic and hydrated minerals [1] Since its arrival at the Octavia E. Butler landing site, the rover explored about 100 meters around it initial landing position and analyzed the local bedrocks surrounding it.Located on the top of the mast of the Perseverance rover is SuperCam, a multipurpose remote sensing instrument able to acquire high resolution color images, infrared, laser-induced breakdown spectroscopy (LIBS) and Raman spectra, and including also a microphone [2, 3]. The LIBS technique is similar to the one used by ChemCam onboard the Curiosity rover, which has been exploring Gale crater since 2012: a powerful laser pulsed at 1064 nm ablates targets at a distance, inducing a plasma spark, the light of which is analyzed by spectroscopy to determine its elemental composition (e.g. [4]). During such an analysis, spectra obtained from the first several laser shots at each location are contaminated by dust deposited on the surface of the rock targets and these spectra are usually removed from further analysis [5]. These spectra present a very homogeneous composition that is different from those of the underlying targets, and are interpreted to represent the analysis of eolian dust deposited over time on the surface of Mars [6].In this study, we compare the spectral results obtained with the SuperCam first shots on the targets analyzed at the Octavia E. Butler landing site with the average first shot spectra obtained by ChemCam on the rock targets at Gale Crater to confirm whether the signal corresponds to a global microns-thick eolian dust cover of Mars.Method: We have used all the LIBS first shot spectra acquired since the landing of Perseverance. This corresponds to ~106 different spectra processed by denoising, background removal, wavelength calibration, and correction for instrument response. The average spectrum obtained from these data can then be appropriately compared with the average first shot spectrum obtained by ChemCam at Gale crater, which was built over 1500 sols (~ 8500 spectra). There is a 2 orders of magnitude difference between the number of first shots acquired by SuperCam and ChemCam at this time, so we can expect the SuperCam results to be less representative than the ChemCam ones. Results: The comparison of the LIBS spectra (Figure 1.) indicate strong similarities in major element compositions The only disparity comes from apparent elevated Mg and Ca lines in the SuperCam signal, which are possibly due to a local contribution. The minor elements, such as H, Li, Mn, Cr, also present peaks with intensities similar to the ones detected on the ChemCam spectrum, indicating a similar level of hydration and minor elements contents of the dust fraction at Jezero and at Gale. While the rocks analyzed by SuperCam at Jezero crater appear visually to be less covered by dust than the ones seen at Gale crater, our analysis indicates that the rocks studied at Jezero remain covered by a thin layer of homogeneous material similar in composition to the eolian deposited dust. This result is consistent with a global mixing of the eolian dust cover on Mars at the micron scale, or possibly a single origin for the eolian dust on Mars as described in previous studies (e.g. [7, 8]).Conclusion: The average of the first LIBS shot spectra acquired by SuperCam at Jezero crater compare very well with the average spectrum of ChemCam’s first shots at Gale crater. The intensity of the emission lines in the two spectra are very similar indicating the probable global mixing of the dust deposited all over the surface of Mars. Figure 1: Comparison of average first shots LIBS spectra of ChemCam at Gale Crater ([6] in red) and average first shots LIBS spectra of SuperCam at Jezero Crater (in blue). A) UV range, B) blue-violet range, C) green range D) orange range E) red range.Acknowledgements: The Perseverance rover and the SuperCam instrument were funded by NASA, CNES and LANL.References: [1] Stack, K. M., et al. (2020) Space Science Reviews, 216(8), 1-47. [2] Maurice, S., et al. (2021) Space Science Reviews, 217(3), 1-108. [3] Wiens, R. C., et al. (2021) Space Science Reviews, 217(1), 1-87. [4] Maurice, S., et al. (2016) Journal of Analytical Atomic Spectrometry, 31(4), 863-889. [5] Clegg, S. M., et al. (2017) Spectrochimica Acta Part B: Atomic Spectroscopy, 129, 64-85. [6] Lasue, J., et al. (2018) Geophysical Research Letters, 45(20), 10-968. [7] Berger, J. A., et al. (2016). Geophysical Research Letters, 43(1), 67-75. [8] Ojha, L., et al. (2018) Nature communications, 9(1), 1-7.
Published: 2021
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5. The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description

Author: I. Torre-Fdez, V. Gharakanian, E. Cordoba, Jérôme Parisot, R. Perez, Amaury Fau, Peter Willis, Ruth A. Anderson, Pablo Sobron, K. W. Wong, A. Debus, Julien Mekki, Noureddine Melikechi, K. Mathieu, S. Gauffre, M. Toplis, Jesús Martínez-Frías, Alexandre Cadu, Francois Poulet, B. Quertier, Horton E. Newsom, H. Seran, C. Quantin-Nataf, W. D’anna, Jens Frydenvang, Frédéric Chapron, Pierre Beck, Jean-François Mariscal, B. Chide, Y. André, Y. Michel, G. Orttner, N. Toulemont, A. Dufour, Briana Lucero, Olivier Gilard, Marion Bonafous, D. Pheav, Q.-M. Lee, D. Standarovsky, Franck Montmessin, R. Gonzalez, S. Le Mouélic, Cedric Virmontois, L. Roucayrol, I. Gontijo, M. Deleuze, L. Parès, L. Oudda, Y. Micheau, F. Manni, Bruno Dubois, Bruno Bousquet, G. de los Santos, D. M. Delapp, Guillermo Lopez-Reyes, L. Picot, Clément Royer, E. Clave, Richard Leveille, Erwin Dehouck, Gaetan Lacombe, J. Javier Laserna, Olivier Beyssac, P. Romano, Y. Daydou, Scott M. McLennan, John Michel, V. Sridhar, Driss Kouach, Gabriel Pont, M. Dupieux, Michel Gauthier, Jean-Michel Reess, J. Moros, J.-C. Dameury, T. Fouchet, Ann Ollila, Sophie Jacquinod, P. Y. Meslin, M. Egan, Juan Manuel Madariaga, Karim Benzerara, G. Hervet, Gilles Montagnac, Woodward W. Fischer, Olivier Gasnault, T. Nelson, Stanley M. Angel, Lauren DeFlores, Violaine Sautter, Marco Veneranda, C. Leyrat, Olivier Humeau, Y. Morizet, Jose Antonio Manrique, M. Sodki, P. Pilleri, C. Velasco, Naomi Murdoch, M. J. Schoppers, S. A. Storms, Sylvestre Maurice, Benigno Sandoval, Cedric Pilorget, N. Striebig, S. Robinson, V. Mousset, David Mimoun, Morten Madsen, M. Heim, A. Doressoundiram, Christophe Montaron, Eric Lewin, Patrick Pinet, C. Donny, Susanne Schröder, Agnès Cousin, Sadok Abbaki, John P. Grotzinger, Claude Collin, Xavier Jacob, Jeffrey R. Johnson, Cécile Fabre, K. McCabe, C. Legett, J. P. Berthias, Shiv K. Sharma, Timothy H. McConnochie, A. Sournac, Ralph D. Lorenz, M. Viso, Yann Parot, N. Mangold, W. Rapin, Jérémie Lasue, Gorka Arana, Joan Ervin, E. Le Comte, N. Nguyen Tuong, P. Cais, Olivier Forni, D. Rambaud, T. Battault, D. Venhaus, Anupam K. Misra, K. Clark, M. Tatat, Laurent Lapauw, P. Bernardi, Roger C. Wiens, Samuel M. Clegg, Nina Lanza, Sylvain Bernard, Soren N. Madsen, Kepa Castro, M. Boutillier, Raymond Newell, D. Granena, Y. Hello, Fernando Rull, M. Ruellan, R. Mathon, Edward A. Cloutis, Gilles Dromart, L. Le Deit, Rafik Hassen-Khodja, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), Universidad de Valladolid [Valladolid] (UVa), Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), University of South Carolina [Columbia], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), University of Winnipeg, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, University of Hawai‘i [Mānoa] (UHM), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), University of Copenhagen = Københavns Universitet (UCPH), Institut de mécanique des fluides de Toulouse (IMFT), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), PLANETO - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universidad de Málaga [Málaga] = University of Málaga [Málaga], Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), McGill University = Université McGill [Montréal, Canada], Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), University of Maryland [College Park], University of Maryland System, Stony Brook University [SUNY] (SBU), State University of New York (SUNY), University of Massachusetts [Lowell] (UMass Lowell), University of Massachusetts System (UMASS), Laboratoire de Planétologie et Géodynamique - Angers (LPG-ANGERS), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), The University of New Mexico [Albuquerque], Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut für Optische Sensorsysteme, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), SETI Institute, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), University of Copenhagen = Københavns Universitet (KU), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées
Subjects: Rocks, 010504 meteorology & atmospheric sciences, Computer science, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Mars, Context (language use), Perseverance, Imaging on Mars, Mars 2020 Perseverance rover, 01 natural sciences, SuperCam Instrument, Unit (housing), Mast (sailing), Jezero crater, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, imaging on Mars, Microphone on Mars, 0103 physical sciences, Calibration, Rover, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], infrared spectroscopy, Raman, 010303 astronomy & astrophysics, Infrared spectroscopy, 0105 earth and related environmental sciences, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], M2020, LIBS, Payload, Suite, Mars2020, Astronomy and Astrophysics, Laser-Induced Breakdown Spectroscopy, Mars Exploration Program, microphone on Mars, Planetary science, SuperCam, Space and Planetary Science, Raman spectroscopy, Systems engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Mars 2020 PERSEVERANCE rover
Abstract: On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data. In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds.
Published: 2021
Full Text: View/download PDF

6. Author Correction: In situ recording of Mars soundscape

Author: Maurice, S., Chide, B., Murdoch, N., Lorenz, R, Mimoun, D., Wiens, R., Stott, A., Jacob, X., Bertrand, T., Montmessin, Franck, Lanza, N, Alvarez-Llamas, C., Angel, S, Aung, M., Balaram, J., Beyssac, O., Cousin, A., Delory, G., Forni, O., Fouchet, T., Gasnault, O., Grip, H., Hecht, M., Hoffman, J., Laserna, J., Lasue, Jérémie, Maki, J., Mcclean, J., Meslin, P.-Y., Le Mouélic, S., Munguira, A., Newman, C., Rodríguez Manfredi, J., Moros, J., Ollila, A., Pilleri, P., Schröder, S., de La Torre Juárez, M., Tzanetos, T., Stack, K., Farley, K., Williford, K., Acosta-Maeda, T., Anderson, R., Applin, D., Arana, G., Bassas-Portus, M., Beal, R., Beck, P., Benzerara, K., Bernard, S., Bernardi, P., Bosak, T., Bousquet, B., Brown, A., Cadu, A., Caïs, P., Castro, K., Clavé, E., Clegg, S, Cloutis, E., Connell, S., Debus, A., Dehouck, E., Delapp, D., Donny, C., Dorresoundiram, A., Dromart, G., Dubois, B., Fabre, C., Fau, A., Fischer, W., Francis, R., Frydenvang, J., Gabriel, T., Gibbons, E., Gontijo, I., Johnson, J., Kalucha, H., Kelly, E., Knutsen, Elise Wright, Lacombe, Gaetan, Legett, C., Leveille, R., Lewin, E., Lopez-Reyes, G., Lorigny, E., Madariaga, J., Madsen, M., Madsen, S., Mandon, L., Mangold, N., Mann, M., Manrique, J.-A., Martinez-Frias, J., Mayhew, L., Mcconnochie, T., Mclennan, S., Melikechi, N., Meunier, F., Montagnac, G., Mousset, V., Nelson, T., Newell, R, Parot, Y., Pilorget, C., Pinet, P., Pont, G., Poulet, F., Quantin-Nataf, C., Quertier, B., Rapin, W., Reyes-Newell, A., Robinson, S., Rochas, L., Royer, C., Rull, F., Sautter, V., Sharma, S., Shridar, V., Sournac, A., Toplis, M., Torre-Fdez, I., Turenne, N., Udry, A., Veneranda, M., Venhaus, D., Vogt, D., Willis, P., Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Earth, Atmospheric, and Planetary Sciences [West Lafayette] (EAPS), Purdue University [West Lafayette], Institut de mécanique des fluides de Toulouse (IMFT), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universidad de Málaga [Málaga] = University of Málaga [Málaga], Department of Chemistry and Biochemistry [Columbia, South Carolina], University of South Carolina [Columbia], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Heliospace Corporation, MIT Haystack Observatory, Massachusetts Institute of Technology (MIT), Department of Aeronautics and Astronautics [Cambridge], Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Escuela de Ingeniería de Bilbao, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Aeolis Corporation, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Optical Sensor Systems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Blue Marble Space Institute of Science (BMSIS), University of Hawai‘i [Mānoa] (UHM), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), University of Winnipeg, University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Plancius Research LLC, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de Lyon, GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), University of Copenhagen = Københavns Universitet (UCPH), McGill University = Université McGill [Montréal, Canada], Universidad de Valladolid [Valladolid] (UVa), IT University of Copenhagen (ITU), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Geological Sciences [Boulder], University of Colorado [Boulder], University of Maryland [College Park], University of Maryland System, Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Department of Physics and Applied Physics [Lowell], University of Massachusetts [Lowell] (UMass Lowell), University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), University of Nevada [Las Vegas] (WGU Nevada), and NASA’s Mars Exploration ProgramCNES
Subjects: Multidisciplinary, Carbon dioxide, Modélisation, [SDU]Sciences of the Universe [physics], Atmospheric Turbulence, Atmospheric Sound, Microphone, Mars, Attenuation, CO2, Perseverance, Acoustic Environment
Abstract: International audience
Published: 2022
Full Text: View/download PDF

7. Post-landing major element quantification using SuperCam laser induced breakdown spectroscopy

Author: Ryan B. Anderson, Olivier Forni, Agnes Cousin, Roger C. Wiens, Samuel M. Clegg, Jens Frydenvang, Travis S.J. Gabriel, Ann Ollila, Susanne Schröder, Olivier Beyssac, Erin Gibbons, David S. Vogt, Elise Clavé, Jose-Antonio Manrique, Carey Legett, Paolo Pilleri, Raymond T. Newell, Joseph Sarrao, Sylvestre Maurice, Gorka Arana, Karim Benzerara, Pernelle Bernardi, Sylvain Bernard, Bruno Bousquet, Adrian J. Brown, César Alvarez-Llamas, Baptiste Chide, Edward Cloutis, Jade Comellas, Stephanie Connell, Erwin Dehouck, Dorothea M. Delapp, Ari Essunfeld, Cecile Fabre, Thierry Fouchet, Cristina Garcia-Florentino, Laura García-Gómez, Patrick Gasda, Olivier Gasnault, Elisabeth M. Hausrath, Nina L. Lanza, Javier Laserna, Jeremie Lasue, Guillermo Lopez, Juan Manuel Madariaga, Lucia Mandon, Nicolas Mangold, Pierre-Yves Meslin, Anthony E. Nelson, Horton Newsom, Adriana L. Reyes-Newell, Scott Robinson, Fernando Rull, Shiv Sharma, Justin I. Simon, Pablo Sobron, Imanol Torre Fernandez, Arya Udry, Dawn Venhaus, Scott M. McLennan, Richard V. Morris, Bethany Ehlmann, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), DLR Institute of Optical Sensor Systems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), McGill University = Université McGill [Montréal, Canada], Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Valladolid [Valladolid] (UVa), University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Plancius Research LLC, Universidad de Málaga [Málaga] = University of Málaga [Málaga], University of Manitoba [Winnipeg], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Nevada [Las Vegas] (WGU Nevada), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), The University of New Mexico [Albuquerque], University of Hawai‘i [Mānoa] (UHM), NASA Johnson Space Center (JSC), NASA, Search for Extraterrestrial Intelligence Institute (SETI), State University of New York at Stony Brook, Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Division of Geological and Planetary Sciences [Pasadena], and California Institute of Technology (CALTECH)
Subjects: LIBS, Mars, Multivariate regression, Laser induced breakdown spectroscopy, Regression, Atomic and Molecular Physics, and Optics, Analytical Chemistry, [SDU]Sciences of the Universe [physics], Calibration, Chemometrics, Laser induced breakdown spectroscopy LIBS Mars Multivariate regression Regression Chemometrics Calibration, Instrumentation, Spectroscopy
Abstract: International audience; The SuperCam instrument on the Perseverance Mars 2020 rover uses a pulsed 1064 nm laser to ablate targets at a distance and conduct laser induced breakdown spectroscopy (LIBS) by analyzing the light from the resulting plasma. SuperCam LIBS spectra are preprocessed to remove ambient light, noise, and the continuum signal present in LIBS observations. Prior to quantification, spectra are masked to remove noisier spectrometer regions and spectra are normalized to minimize signal fluctuations and effects of target distance. In some cases, the spectra are also standardized or binned prior to quantification. To determine quantitative elemental compositions of diverse geologic materials at Jezero crater, Mars, we use a suite of 1198 laboratory spectra of 334 well-characterized reference samples. The samples were selected to span a wide range of compositions and include typical silicate rocks, pure minerals (e.g., silicates, sulfates, carbonates, oxides), more unusual compositions (e.g., Mn ore and sodalite), and replicates of the sintered SuperCam calibration targets (SCCTs) onboard the rover. For each major element (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), the database was subdivided into five "folds" with similar distributions of the element of interest. One fold was held out as an independent test set, and the remaining four folds were used to optimize multivariate regression models relating the spectrum to the composition. We considered a variety of models, and selected several for further investigation for each element, based primarily on the root mean squared error of prediction (RMSEP) on the test set, when analyzed at 3 m. In cases with several models of comparable performance at 3 m, we incorporated the SCCT performance at different distances to choose the preferred model. Shortly after landing on Mars and collecting initial spectra of geologic targets, we selected one model per element. Subsequently, with additional data from geologic targets, some models were revised to ensure results that are more consistent with geochemical constraints. The calibration discussed here is a snapshot of an ongoing effort to deliver the most accurate chemical compositions with SuperCam LIBS.
Published: 2022
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8. Grid-based mapping: A method for rapidly determining the spatial distributions of small features over very large areas

Author: Matthew R. Balme, E. Hauber, Antoine Séjourné, Zuzanna M. Swirad, Anna Losiak, Andreas Johnsson, Stephan van Gasselt, Ákos Kereszturi, Jason Ramsdale, François Costard, Isaac B. Smith, Colman Gallagher, Thomas Platz, James A. Skinner, Csilla Orgel, Susan J. Conway, Dennis Reiss, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), UCD School of Geography, UCD Earth Institute, University College, University College Dublin [Dublin] (UCD), Freie Universität Berlin, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Department of Earth Sciences [Gothenburg], University of Gothenburg (GU), Institute of Geological Sciences [Wrocław] (UWr), University of Wrocław [Poland] (UWr), Department of Lithospheric Research [Wien], Universität Wien, Institut für Planetologie [Münster], Westfälische Wilhelms-Universität Münster (WWU), Department of Geography, Durham University, Durham University, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA), Institute for Geophysics, University of Texas, University of Texas at Austin [Austin], Max-Planck-Institut für Sonnensystemforschung (MPS), and Max-Planck-Gesellschaft
Subjects: 010504 meteorology & atmospheric sciences, Glacial landform, Mars, Context (language use), 01 natural sciences, 0103 physical sciences, 010303 astronomy & astrophysics, Spatial analysis, 0105 earth and related environmental sciences, Remote sensing, geography, geography.geographical_feature_category, Landform, Astronomy and Astrophysics, computer.file_format, 15. Life on land, Grid, grid mapping, Phytogeomorphology, Mapping, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Raster graphics, Scale (map), computer, Geology
Abstract: International audience; The increased volume, spatial resolution, and areal coverage of high-resolution images of Mars over the past 15 years have led to an increased quantity and variety of small-scale landform identifications. Though many such landforms are too small to represent individually on regional-scale maps, determining their presence or absence across large areas helps form the observational basis for developing hypotheses on the geological nature and environmental history of a study area. The combination of improved spatial resolution and near-continuous coverage significantly increases the time required to analyse the data. This becomes problematic when attempting regional or global-scale studies of metre and decametre-scale landforms. Here, we describe an approach for mapping small features (from decimetre to kilometre scale) across large areas, formulated for a project to study the northern plains of Mars, and provide context on how this method was developed and how it can be implemented. Rather than “mapping” with points and polygons, grid-based mapping uses a “tick box” approach to efficiently record the locations of specific landforms (we use an example suite of glacial landforms; including viscous flow features, the latitude dependant mantle and polygonised ground). A grid of squares (e.g. 20 km by 20 km) is created over the mapping area. Then the basemap data are systematically examined, grid-square by grid-square at full resolution, in order to identify the landforms while recording the presence or absence of selected landforms in each grid-square to determine spatial distributions. The result is a series of grids recording the distribution of all the mapped landforms across the study area. In some ways, these are equivalent to raster images, as they show a continuous distribution-field of the various landforms across a defined (rectangular, in most cases) area. When overlain on context maps, these form a coarse, digital landform map. We find that grid-based mapping provides an efficient solution to the problems of mapping small landforms over large areas, by providing a consistent and standardised approach to spatial data collection. The simplicity of the grid-based mapping approach makes it extremely scalable and workable for group efforts, requiring minimal user experience and producing consistent and repeatable results. The discrete nature of the datasets, simplicity of approach, and divisibility of tasks, open up the possibility for citizen science in which crowdsourcing large grid-based mapping areas could be applied.
Published: 2017
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9. Photometric changes on Saturn's Titan: Evidence for active cryovolcanism

Author: Dale P. Cruikshank, Angioletta Coradini, F. Leader, Pierre Drossart, Karl L. Mitchell, P. Cerroni, Robert M. Nelson, Randolph L. Kirk, Dennis L. Matson, Stephen D. Wall, Fabrizio Capaccioni, John C. Pearl, Kevin H. Baines, Vito Mennella, M. Combes, P. D. Nicholson, Gianrico Filacchione, M. D. Boryta, Ralf Jaumann, L. W. Kamp, Yves Langevin, Rosaly M. C. Lopes, Bruno Sicardy, Thomas B. McCord, Jonathan I. Lunine, Vittorio Formisano, Jean-Pierre Bibring, Roger N. Clark, Bruce Hapke, Patrick G. J. Irwin, Christophe Sotin, Giancarlo Bellucci, William D. Smythe, Jet Propulsion Laboratory, California Institute of Technology (JPL), US Geological Survey, Flagstaff, Department of Geology and Planetary Science, University of Pittsburgh, Department of Earth Science and Astronomy, Mt. San Antonio College, Walnut, Institute for Planetary Exploration, Deutsches Zentrum for Luft und Raumfahrt, United States Geological Survey, Denver, SETI Institute, NASA Ames Research Center, Moffett Field, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), ISFI, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Bear Fight Center, Space Science Institute, Winthrop, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), Department of Astronomy, Cornell University, Clarendon Laboratory, Department of Physics, University of Oxford, and NASA/Goddard Space Flight Center (NASA/GSFC)
Subjects: Synthetic aperture radar, Spectrometer, Infrared, cryovolcanism, law.invention, Astrobiology, Photometry, Orbiter, symbols.namesake, Geophysics, law, symbols, General Earth and Planetary Sciences, Titan, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Titan (rocket family), Geology, Remote sensing
Abstract: International audience; We report infrared spectrophotometric variability on the surface of Saturn's moon Titan detected in images returned by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini Saturn Orbiter. The changes were observed at 7°S, 138°W and occurred between October 27, 2005 and January 15, 2006. After that date the surface was unchanged until the most recent observation, March 18, 2006. We previously reported spectrophotometric variability at another location (26°S, 78°W). Cassini Synthetic Aperture RADAR (SAR) images find that the surface morphology at both locations is consistent with surface flows possibly resulting from cryovolcanic activity (Wall et al., companion paper, this issue). The VIMS-reported time variability and SAR morphology results suggest that Titan currently exhibits intermittent surface changes consistent with present ongoing surface processes. We suggest that these processes involve material from Titan's interior being extruded or effused and deposited on the surface, as might be expected from cryovolcanism.
Published: 2016
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10. Transient surface liquid in Titan’s polar regions from Cassini

Author: THE CASSINI RADAR TEAM, HAYES, A. G., AHARONSON, O., LUNINE, J.I., KIRK, R. L., ZEBKER, H. A., WYE, L. C., LORENZ, R. D., TURTLE, E. P., PAILLOU, Philippe, MITRI, G., WALL, S. D., STOFAN, E. R., MITCHELL, K. L., ELACHI, C., Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Department of Electrical Engineering [Stanford], Stanford University, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), and Proxemy Research Inc
Subjects: Shore, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Atmospheric circulation, Climate oscillation, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Atmospheric sciences, 01 natural sciences, symbols.namesake, 13. Climate action, Space and Planetary Science, Radar imaging, 0103 physical sciences, symbols, Polar, Exponential decay, Water cycle, Titan (rocket family), 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Cassini RADAR images of Titan's south polar region acquired during southern summer contain lake features which disappear between observations. These features show a tenfold increases in backscatter cross-section between images acquired one year apart, which is inconsistent with common scattering models without invoking temporal variability. The morphologic boundaries are transient, further supporting changes in lake level. These observations are consistent with the exposure of diffusely scattering lakebeds that were previously hidden by an attenuating liquid medium. We use a two-layer model to explain backscatter variations and estimate a drop in liquid depth of approximately 1-m-per-year. On larger scales, we observe shoreline recession between ISS and RADAR images of Ontario Lacus, the largest lake in Titan's south polar region. The recession, occurring between June 2005 and July 2009, is inversely proportional to slopes estimated from altimetric profiles and the exponential decay of near-shore backscatter, consistent with a uniform reduction of 4 ± 1.3 m in lake depth.Of the potential explanations for observed surface changes, we favor evaporation and infiltration. The disappearance of dark features and the recession of Ontario's shoreline represents volatile transport in an active methane-based hydrologic cycle. Observed loss rates are compared and shown to be consistent with available global circulation models. To date, no unambiguous changes in lake level have been observed between repeat images in the north polar region, although further investigation is warranted. These observations constrain volatile flux rates in Titan's hydrologic system and demonstrate that the surface plays an active role in its evolution. Constraining these seasonal changes represents the first step toward our understanding of longer climate cycles that may determine liquid distribution on Titan over orbital time periods.
Published: 2011
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11. Regulating continent growth and composition by chemical weathering

Author: William P. Leeman, Mark G. Little, Arnaud Agranier, Ronald W. Kistler, Cin-Ty A. Lee, U. N. Horodyskyj, Douglas M. Morton, Department of Earth Science [Houston], Rice University [Houston], US Geological Survey [Riverside], United States Geological Survey [Reston] (USGS), US Geological Survey [Flagstaff], Department of Geological Sciences [Providence], Brown University, Earth Science Division, National Science Foundation [Arlington] (NSF), Domaines Océaniques (LDO), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS)
Subjects: Basalt, Multidisciplinary, 010504 meteorology & atmospheric sciences, Subduction, [SDE.MCG]Environmental Sciences/Global Changes, Crustal recycling, Geochemistry, crust, Weathering, Crust, continent, 010502 geochemistry & geophysics, 01 natural sciences, igneous, Igneous rock, lithium, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 13. Climate action, Physical Sciences, Igneous differentiation, Seabed, Geology, geochemistry, 0105 earth and related environmental sciences
Abstract: International audience; Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms.
Published: 2008
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12. Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper

Author: G. Boubin, Michael Allison, Ellen R. Stofan, Charles Elachi, G. Hamilton, Steven J. Ostro, L. Roth, Randolph L. Kirk, William T. K. Johnson, Stephen D. Wall, Y. Anderson, S. Shaffer, Roberto Seu, Philip S. Callahan, Lauren Wye, R. Boehmer, Bryan Stiles, Gian Gabriele Ori, Jani Radebaugh, Karl L. Mitchell, Giovanni Picardi, Howard A. Zebker, Laurence A. Soderblom, Duane O. Muhleman, Richard West, S. Vetrella, Enrico Flamini, R. D. Lorenz, Roberto Orosei, Andrew Dominic Fortes, Jonathan I. Lunine, Yonggyu Gim, K. Kelleher, L. E. Robshaw, Catherine D. Neish, E. Reffet, Pierre Encrenaz, Scott Hensley, Flora Paganelli, Michael Janssen, Rosaly M. C. Lopes, Francesco Posa, Charles A. Wood, G. Francescetti, Jet Propulsion Laboratory, California Institute of Technology (JPL), Proxemy Research, Bowie, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), US Geological Survey, Flagstaff, Wheeling Jesuit University, Environmental Sciences Department, Lancaster University, University College of London [London] (UCL), Goddard Institute for Space Studies, National Aeronautics and Space Administration New York, Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Agenzia Spaziale Italiana (ASI), Facoltá di Ingegneria, Geological and Planetary Sciences, California Institute of Technology, Pasadena, International Research School of Planetary Sciences, Dipartimento di Scienze, Università d'Annunzio, Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Universitá La Sapienza, INFM and Dipartimento Interateneo di Fisica, and Stanford University
Subjects: Synthetic aperture radar, Solar System, geography, satellites of saturn, titan, volcanism, geography.geographical_feature_category, biology, Lava, Astronomy and Astrophysics, Venus, biology.organism_classification, Astrobiology, law.invention, symbols.namesake, Volcano, Space and Planetary Science, law, Radar imaging, symbols, Radar, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Titan (rocket family), Geology
Abstract: International audience; The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar images of Titan's surface during four fly-bys during the mission's first year. These images show that Titan's surface is very complex geologically, showing evidence of major planetary geologic processes, including cryovolcanism. This paper discusses the variety of cryovolcanic features identified from SAR images, their possible origin, and their geologic context. The features which we identify as cryovolcanic in origin include a large (180 km diameter) volcanic construct (dome or shield), several extensive flows, and three calderas which appear to be the source of flows. The composition of the cryomagma on Titan is still unknown, but constraints on rheological properties can be estimated using flow thickness. Rheological properties of one flow were estimated and appear inconsistent with ammonia-water slurries, and possibly more consistent with ammonia-water-methanol slurries. The extent of cryovolcanism on Titan is still not known, as only a small fraction of the surface has been imaged at sufficient resolution. Energetic considerations suggest that cryovolcanism may have been a dominant process in the resurfacing of Titan.
Published: 2007
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13. The Sand Seas of Titan: Cassini RADAR Observations of Longitudinal Dunes

Author: Howard A. Zebker, L. Roth, Ralph D. Lorenz, Bryan Stiles, Charles Elachi, Y. Anderson, Ellen R. Stofan, Roberto Seu, K. Kelleher, Giovanni Picardi, Gian Gabriele Ori, K. L. Mitchell, E. Reffet, Duane O. Muhleman, Jonathan I. Lunine, Jani Radebaugh, Enrico Flamini, G. Boubin, Yonggyu Gim, Lauren Wye, S. D. Wall, G. Francescetti, Robert West, Matthew A. Allison, S. Vetrella, Rosaly M. C. Lopes, G. Hamilton, Philip S. Callahan, Laurence A. Soderblom, R. Boehmer, S. Shaffer, Steven J. Ostro, Randolph L. Kirk, Pierre Encrenaz, Scott Hensley, M. A. Janssen, Flora Paganelli, William L. Johnson, Francesco Posa, Charles A. Wood, R. D., Lorenz, S., Wall, J., Radebaugh, G., Boubin, E., Reffet, M., Janssen, E., Stofan, R., Lope, R., Kirk, C., Elachi, J., Lunine, K., Mitchell, F., Paganelli, L., Soderblom, C., Wood, L., Wye, H., Zebker, Y., Anderson, S., Ostro, M., Allison, R., Boehmer, P., Callahan, P., Encrenaz, G. G., Ori, Franceschetti, Giorgio, Y., Gim, G., Hamilton, S., Hensley, W., Johnson, K., Kelleher, D., Muhleman, G., Picardi, F., Posa, L., Roth, R., Seu, S., Shaffer, B., Stile, Vetrella, Sergio, E., Flamini, R., West, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Jet Propulsion Laboratory, California Institute of Technology (JPL), Proxemy Research, Bowie, US Geological Survey, Flagstaff, Planetary Science Institute, Tucson, AZ 85719, USA and Wheeling Jesuit College, Wheeling, Stanford University, Goddard Institute for Space Studies, National Aeronautics and Space Administration New York, Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), International Research School of Planetary Sciences, Dipartimento di Scienze, Università d'Annunzio, Facoltá di Ingegneria, Geological and Planetary Sciences, California Institute of Technology, Pasadena, Universitá La Sapienza, Istituto Nazionale per la Fisica della Materia (INFM) and Dip. Interateneo di Fisica, and Agenzia Spaziale Italiana (ASI)
Subjects: Geologic Sediments, Radar, Multidisciplinary, Extraterrestrial Environment, Titan moon, Wind, Hydrocarbons, Radar observations, Radar imaging, Wavelength, symbols.namesake, Saturn, Surface winds, symbols, Cassini, Particle Size, Spacecraft, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Titan (rocket family), Methane, Geomorphology, Geology, Remote sensing
Abstract: The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show approximately 100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills. The distribution and orientation of the dunes support a model of fluctuating surface winds of approximately 0.5 meter per second resulting from the combination of an eastward flow with a variable tidal wind. The existence of dunes also requires geological processes that create sand-sized (100- to 300-micrometer) particulates and a lack of persistent equatorial surface liquids to act as sand traps.
Published: 2006
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14. Radar: The Cassini Titan Radar Mapper

Author: Steven J. Ostro, Randolph L. Kirk, Laurence A. Soderblom, L. Borgarelli, Giovanni Picardi, M. A. Janssen, Duane O. Muhleman, Pierre Encrenaz, Francesco Posa, L.E. Roth, Charles A. Wood, Chris Rapley, Michael Allison, Ralph D. Lorenz, Jonathan I. Lunine, William T. K. Johnson, Charles Elachi, Howard A. Zebker, Eastwood Im, Roberto Seu, S. Vetrella, S. D. Wall, C., Elachi, M. D., Allison, L., Borgarelli, E., Encrenaz, E., Im, M. A., Janssen, W. T. K., Johnson, R. L., Kirk, R. D., Lorenz, J. I., Lunine, D. O., Muhleman, S. J., Ostro, G., Picardi, F., Posa, C. G., Rapley, L. E., Roth, R., Seu, L. A., Soderblom, Vetrella, Sergio, S. D., Wall, C. A., Wood, H. A., Zebker, Jet Propulsion Laboratory, California Institute of Technology (JPL), Goddard Institute for Space Studies, National Aeronautics and Space Administration New York, Alenia Aerospazio, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), US Geological Survey, Flagstaff, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Geological and Planetary Sciences, California Institute of Technology, Pasadena, Universitá La Sapienza, Dipartimento Interateneo di Fisica, Politecnico di Bari, British Antarctic Survey, Natural Environment Research Council, Facoltá di Ingegneria, University of North Dakota, and Stanford University
Subjects: Radar altimeter, Titan moon, Astronomy and Astrophysics, Scatterometer, Space-based radar, law.invention, Radar engineering details, Radar astronomy, Space and Planetary Science, law, Radar imaging, 3D radar, Cassini, Radar, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Remote sensing
Abstract: International audience; The Cassini RADAR instrument is a multimode 13.8 GHz multiple-beam sensor that can operate as a synthetic-aperture radar (SAR) imager, altimeter, scatterometer, and radiometer. The principal objective of the RADAR is to map the surface of Titan. This will be done in the imaging, scatterometer, and radiometer modes. The RADAR altimeter data will provide information on relative elevations in selected areas. Surfaces of the Saturn's icy satellites will be explored utilizing the RADAR radiometer and scatterometer modes. Saturn's atmosphere and rings will be probed in the radiometer mode only. The instrument is a joint development by JPL/NASA and ASI. The RADAR design features significant autonomy and data compression capabilities. It is expected that the instrument will detect surfaces with backscatter coefficient as low as -40 dB.
Published: 2004
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15. High manganese concentrations in rocks at Gale crater, Mars

Author: Horton E. Newsom, Nicolas Mangold, Craig Hardgrove, Marion Nachon, Stéphane Le Mouélic, Jeff A. Berger, Benton C. Clark, Ann Ollila, John P. Grotzinger, Noureddine Melikechi, S. Maurice, Ryan B. Anderson, Violaine Sautter, Olivier Forni, Roger C. Wiens, Samuel M. Clegg, Woodward W. Fischer, Mariek E. Schmidt, Agnes Cousin, Ralf Gellert, Nina Lanza, Los Alamos National Laboratory (LANL), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Institute of Meteoritics [Albuquerque] (IOM), The University of New Mexico [Albuquerque], Now at Chevron Energy Technology Company, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Space Science Institute [Boulder] (SSI), Department of Physics [Guelph], University of Guelph, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences [St. Catharines], Brock University [Canada], Department of Earth Sciences [London, ON], University of Western Ontario (UWO), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), Department of Physics and Engineering, Delaware State University (DSU), Muséum national d'Histoire naturelle (MNHN), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Geochemistry, chemistry.chemical_element, Weathering, Manganese, Mars Exploration Program, 01 natural sciences, Redox, Astrobiology, Redox indicator, Geophysics, chemistry, 13. Climate action, [SDU]Sciences of the Universe [physics], Martian surface, 0103 physical sciences, Oxidizing agent, General Earth and Planetary Sciences, Composition of Mars, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; The surface of Mars has long been considered a relatively oxidizing environment, an ideasupported by the abundance of ferric iron phases observed there. However, compared to iron, manganeseis sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specificredox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosityrover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitudehigher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-richphase. These results show that the Martian surface has at some point in time hosted much more highlyoxidizing conditions than has previously been recognized
Published: 2014
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16. Introduction to the fifth Mars Polar Science special issue: Key questions, needed observations, and recommended investigations

Author: Pete Smith, William B. Durham, Leslie K. Tamppari, Richard W. Zurek, François Forget, Stephen M. Clifford, David A. Fisher, Shane Byrne, Michael H. Hecht, Kenji Yoshikawa, Timothy N. Titus, Lunar and Planetary Institute [Houston] (LPI), University of Alaska [Fairbanks] (UAF), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), University of Ottawa, Dept. of Geology, Marion Hall, Ottawa , ON, Canada, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), MIT Haystack Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Astronomy and Astrophysics, Mars Exploration Program, Atmosphere of Mars, Mars surface, 01 natural sciences, Astrobiology, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Space and Planetary Science, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 0103 physical sciences, Key (cryptography), [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2013
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17. Observations of Titan’s Northern lakes at 5μm: Implications for the organic cycle and geology

Author: B. Reinhardt, Robert H. Brown, L. A. Soderblom, Katrin Stephan, Bonnie J. Buratti, K. J. Lawrence, Jason M. Soderblom, Roger N. Clark, S. Rodriguez, Christophe Sotin, P. D. Nicholson, Ralf Jaumann, Alexander Hayes, Jason W. Barnes, S. Le Mouélic, Kevin H. Baines, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Centre de physique moléculaire optique et hertzienne (CPMOH), Université Sciences et Technologies - Bordeaux 1 (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Denver], United States Geological Survey [Reston] (USGS), US Geological Survey [Flagstaff], DLR Institute of Planetary Research, German Aerospace Center (DLR), and Cornell University [New York]
Subjects: Synthetic aperture radar, Haze, Titan hydrology, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Atmospheric methane, Organic chemistry, Astronomy and Astrophysics, Atmospheric sciences, Methane, Aerosol, law.invention, symbols.namesake, chemistry.chemical_compound, chemistry, Space and Planetary Science, law, Exobiology, symbols, Atmosphere of Titan, Radar, Titan atmosphere, Titan (rocket family), Titan, Geology
Abstract: International audience; Since Titan entered Northern spring in August 2009, the North Pole has been illuminated allowing observations at optical wavelengths. On June 5, 2010 the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft observed the Northern Pole area with a pixel size from 3 to 7 km. Since, as we demonstrate, little of the solar flux at 5 μm is scattered by the atmosphere, these observations were obtained at relatively large incidence angles and allowed us to build a mosaic covering an area of more than 500,000 km2 that overlaps and complements observations made by the Synthetic Aperture Radar (SAR) in 2007. We find that there is an excellent correlation between the shape of the radar dark area, known as Ligeia Mare and the VIMS 5-μm dark unit. Matching most of the radar shoreline, the 2010 VIMS observations suggest that the 125,000-km2 surface area of Ligeia Mare measured by RADAR in 2007 has not significantly changed. The VIMS observations complement the radar observations to the west of Ligeia Mare and suggest that Ligeia Mare is connected to Kraken Mare by either a diffuse network similar to a swamp area, or by well-defined, sub-pixel rivers. Considering the results of recent evaporation models of methane, our preferred interpretation of the relative constancy in surface area of Ligeia is that it is principally composed of ethane although we cannot rule out the possibility that methane evaporation is balanced with replenishment by either precipitation or underground seepage. There is also strong correlation between the location of the small radar lakes and the small VIMS 5-μm dark patches. The geographic location of the small lakes are within a VIMS pixel of the SAR location, suggesting that the non-synchronous component of Titan’s spin rate, if it exists, was less than 2.3 × 10−4 deg/day between 2007 and 2010 in agreement with the recent T64 radar observations. These observations question the existence of non-synchronous rotation. Two radar-bright features appear dark at 5-μm. The simplest interpretation is that these are very shallow lakes, less than one meter deep. Three new small lakes, named Freeman, Cardiel, and Towada by the IAU, are found outside of the area mapped with the SAR. A single-scattering model describing reflection of sunlight at 5-μm suggests that the lake surface is mirror-like and that the albedo of the solid surfaces surrounding the lakes is about 8%. These observations together with information of the haze aerosols allow us to show that Titan’s lakes, atmospheric ethane and aerosol haze are smaller carbon reservoirs than Titan’s sand dunes and atmospheric methane. A simple model involving an outburst of methane a few hundreds of Myr ago followed by the dissociation of methane in the atmosphere leading to the formation of the haze particles that constitute the dune fields would be consistent with both the present observations and recent measurements of isotopic ratios in atmospheric methane (Mandt, K.E. et al. [2012]. Astrophys. J. 749(160), 14).
Published: 2012
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18. Erratum to: Reports of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2006 & 2009

Author: Régis Courtin, Toshio Fukushima, Peter C. Thomas, David J. Tholen, G. A. Krasinsky, Brent A. Archinal, Al Conrad, Philip J. Stooke, P. K. Seidelmann, Daniel Hestroffer, Guy J. Consolmagno, Michael F. A'Hearn, Juergen Oberst, Iwan P. Williams, J. L. Hilton, Gregory A. Neumann, US Geological Survey, Flagstaff, University of Maryland, Max-Planck-Institut für Astronomie (MPIA), Vatican Observatory, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), National Astronomical Observatory of Japan (NAOJ), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, United States Naval Observatory (USNO), Institute of Applied Astronomy, NASA/Goddard Space Flight Center (NASA/GSFC), Deutsches Zentrum für Luft- und Raumfahrt (DLR), University of Virginia, Department of Physics and Astronomy, University of Western Ontario, University of Hawaii, Hilo, Department of Astronomy, Cornell University, and Queen Mary University of London, Mile End Road
Subjects: Physics, Computational Mathematics, Space and Planetary Science, Group (mathematics), Applied Mathematics, Modeling and Simulation, Astronomy and Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Cartography, Mathematical Physics
Abstract: The primary poles for (243) Ida and (134340) Pluto and its satellite (134340) Pluto : I Charon were redefined in the IAU Working Group on Cartographic Coordinates and Rotational Elements (WGCCRE) 2006 report (Seidelmann et al. in Celest Mech Dyn Astr 98:155, 2007), and 2009 report (Archinal et al. in Celest Mech Dyn Astr 109:101, 2011), respectively, to be consistent with the primary poles of similar Solar System bodies. However, the WGCCRE failed to take into account the effect of the redefinition of the poles on the values of the rotation angle W at J2000.0. The revised relationships in Table 3 of Archinal et al. 2011) are $$\begin{array}{llll} W & = & 274^{\circ}.05 +1864^{\circ}.6280070\, d\;{\rm for\; (243)\,Ida} \\ W & = & 302^{\circ} .695 + 56^{\circ} .3625225\, d\;{\rm for\; (134340)\,Pluto,\; and}\\ W & = & 122^{\circ} .695 + 56^{\circ} .3625225\, d\;{\rm for\; (134340)\,Pluto : I \,Charon}\end{array}$$ where d is the time in TDB days from J2000.0 (JD2451545.0).
Published: 2011
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19. Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009

Author: J. L. Hilton, Brent A. Archinal, Edward Bowell, Peter C. Thomas, P. K. Seidelmann, Régis Courtin, Guy J. Consolmagno, G. A. Krasinsky, Tetsuya Fukushima, Gregory A. Neumann, Daniel Hestroffer, Michael F. A'Hearn, Juergen Oberst, Iwan P. Williams, Philip J. Stooke, David J. Tholen, Al Conrad, US Geological Survey, Flagstaff, University of Maryland, Lowell Observatory, Flagstaff, W. M. Keck Observatory, Vatican Observatory, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), National Astronomical Observatory of Japan (NAOJ), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), United States Naval Observatory (USNO), Institute of Applied Astronomy, NASA/Goddard Space Flight Center (NASA/GSFC), Deutsches Zentrum für Luft- und Raumfahrt (DLR), University of Virginia, Department of Physics and Astronomy, University of Western Ontario, University of Hawaii, Hilo, Department of Astronomy, Cornell University, and Queen Mary University of London, Mile End Road
Subjects: Astrophysics and Astronomy, Satellites, Dwarf planet, Planets, Rotation periods, Jupiter, Planet, Saturn, Orientation (geometry), Comets, Mathematical Physics, Mathematics, Dwarf planets, Latitude, Geography, Applied Mathematics, Astronomy, Minor planets, Astronomy and Astrophysics, Planetary system, Geodesy, Computational Mathematics, Longitude, Space and Planetary Science, Asteroid, Modeling and Simulation, Physics::Space Physics, Rotation axes, Sizes, Astrophysics::Earth and Planetary Astrophysics, Shapes, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Cartography, Rotation (mathematics), Cartographic coordinates
Abstract: International audience; Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars' satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Steins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the general planetary community regarding the need for controlled products, and improved or consensus rotation models for Mars, Jupiter, and Saturn.
Published: 2010
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20. Dune material budget and distribution on Titan using Cassini radar and radiometry observations (Invited)

Author: Janssen, M. A., Wye, L., Hayes, A. G., Lorenz, R. D., Radebaugh, J., Lunine, J.I., Kirk, R. L., Lopes, R. M., Wall, S. D., Stofan, E. R., Farr, T. G., Paillou, Philippe, Cassini Radar Team, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Stanford University, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Proxemy Research Inc, SSE 2010, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)
Subjects: Surface materials and properties, [6281] PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [5470] PLANETARY SCIENCES: SOLID SURFACE PLANETS, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [5464] PLANETARY SCIENCES: SOLID SURFACE PLANETS, Erosion and weathering, Remote sensing, [5415] PLANETARY SCIENCES: SOLID SURFACE PLANETS, Titan
Abstract: International audience; Titan's equatorial regions are covered by vast fields of longitudinal dunes. Several observations point to solid hydrocarbons as the most likely candidate for the dune particle composition. Together with the polar lakes and seas, dune regions are thus the main reservoir of organic deposits on Titan. A refined estimate of the dune material volume and distribution is essential to constrain Titan total organic inventory and therefore to understand the carbon cycle on Titan. Using Cassini SAR observations we find that Titan's dune fields are generally hosted by basins and may cover ~12.5% of Titan's surface, which corresponds to an area of ~10 million km2 (roughly the area of the United States). Polarized radiometry observations indicate that dune particles are mainly composed of organic solids, consistent with spectroscopic measurements. This would imply that the dune particles were dominantly created by atmospheric photochemical production rather than fluvial erosion. However, it is not clear whether the aggregation occurred primarily during aerosol sedimentation from the stratosphere to the surface, or by subsequent sticking and growth during fluvial or eolian transport. Assuming that, everywhere, the dunes are 100m-high and that the interdunes spaces are clear of dune material and of equal area than the dunes, the volume of sand-sized sediments should approach ~250 000 km3, which is an order of magnitude higher than the current estimate of the volume of liquid hydrocarbons on Titan (Lorenz et al., 2008). However, the combined radar and radiometry measurements indicate regional variations among the dunes. In this paper we will show that differences in the microwave backscatter and emission of the dune regions can be well explained by various degrees of exposure of the icy bedrock of Titan in the interdunal corridors. In some regions, a thick sheet of sand-sized material covers the interdunes. In other places, the original substrate is peeking through. These variations need to be taken into account in order to estimate the volume of sand-sized sediments. Investigating them also bring new insights on the distribution of the available sand-sized sediments supply, which vary across Titan probably owing to differences in the ground humidity and wind patterns.
Published: 2010

21. Active shoreline of Ontario Lacus, Titan: A morphological study of the lake and its surroundings

Author: WALL, S., HAYES, A., BRISTOW, C., LORENZ, R., STOFAN, E., LUNINE, J., LE GALL, Alice, JANSSEN, M., LOPES, R., WYE, L., SODERBLOM, L., PAILLOU, Philippe, AHARONSON, O., ZEBKER, H., FARR, T., MITRI, G., KIRK, R., MITCHELL, K., NOTARNICOLA, C., CASARANO, D., VENTURA, B., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Department of Earth and Planetary Sciences [UCL/Birkbeck], Birkbeck College [University of London], Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Proxemy Research Inc, Stanford University, US Geological Survey [Denver], United States Geological Survey [Reston] (USGS), US Geological Survey [Flagstaff], Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1, Department of Electrical Engineering [Stanford], Institute of Applied Remote Sensing [Bozano}, European Academy Bozen/Bolzano (EURAC), Istituto di Ricerca per la Protezione Idrogeologica [Bari] (IRPI), Consiglio Nazionale delle Ricerche [Roma] (CNR), Fachbereich Geowissenschaften [Bremen], and Universität Bremen
Subjects: Planetary Sciences: Solid Surface Planets: Surface materials and properties, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Planetary Sciences: Solid Surface Planets: Hydrology and fluvial processes, Planetary Sciences: Solid Surface Planets: Remote sensing
Abstract: International audience; Of more than 400 filled lakes now identified on Titan, the first and largest reported in the southern latitudes is Ontario Lacus, which is dark in both infrared and microwave. Here we describe recent observations including synthetic aperture radar (SAR) images by Cassini's radar instrument (λ = 2 cm) and show morphological evidence for active material transport and erosion. Ontario Lacus lies in a shallow depression, with greater relief on the southwestern shore and a gently sloping, possibly wave-generated beach to the northeast. The lake has a closed internal drainage system fed by Earth-like rivers, deltas and alluvial fans. Evidence for active shoreline processes, including the wave-modified lakefront and deltaic deposition, indicates that Ontario is a dynamic feature undergoing typical terrestrial forms of littoral modification.
Published: 2010
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22. Bathymetry and absorptivity of Titan's Ontario Lacus

Author: Alexander G. Hayes, Oded Aharonson, Lauren Wye, Philippe Paillou, Howard A. Zebker, Ralph D. Lorenz, Charles Elachi, Jonathan I. Lunine, Philip S. Callahan, Aaron S. Wolf, R. L. Kirk, S. D. Wall, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Department of Electrical Engineering [Stanford], Stanford University, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), and NASA-California Institute of Technology (CALTECH)
Subjects: Synthetic aperture radar, Atmospheric Science, Planetary Sciences: Solid Surface Planets: Surface materials and properties, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Soil Science, Aquatic Science, Oceanography, 01 natural sciences, law.invention, symbols.namesake, Geochemistry and Petrology, law, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Bathymetry, Radio Science: Radio wave propagation, Altimeter, Radar, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Shore, geography, geography.geographical_feature_category, Ecology, Attenuation, Paleontology, Forestry, Geophysics, Molar absorptivity, Planetary Sciences: Solid Surface Planets: Hydrology and fluvial processes, Planetary Sciences: Solid Surface Planets: Remote sensing, Planetary Sciences: Solar System Objects: Titan, Space and Planetary Science, symbols, Titan (rocket family), Geology
Abstract: International audience; Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June and July 2009, the Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of the area. Together with closest approach altimetry acquired in December 2008, these observations provide a unique opportunity to study the lake's nearshore bathymetry and complex refractive properties. Average radar backscatter is observed to decrease exponentially with distance from the local shoreline. This behavior is consistent with attenuation through a deepening layer of liquid and, if local topography is known, can be used to derive absorptive dielectric properties. Accordingly, we estimate nearshore topography from a radar altimetry profile that intersects the shoreline on the East and West sides of the lake. We then analyze SAR backscatter in these regions to determine the imaginary component of the liquid's complex index of refraction ($\kappa$). The derived value, $\kappa$ = (6.1‑1.3+1.7) × 10‑4, corresponds to a loss tangent of tan Δ = (9.2‑2.0+2.5) × 10‑4 and is consistent with a composition dominated by liquid hydrocarbons. This value can be used to test compositional models once the microwave optical properties of candidate materials have been measured. In areas that do not intersect altimetry profiles, relative slopes can be calculated assuming the index of refraction is constant throughout the liquid. Accordingly, we construct a coarse bathymetry map for the nearshore region by measuring bathymetric slopes for eleven additional areas around the lake. These slopes vary by a factor of ∼5 and correlate well with observed shoreline morphologies.
Published: 2010
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23. Titan's inventory of organic surface materials

Author: Oded Aharonson, Stephen D. Wall, Bryan Stiles, Michael Janssen, Rosaly M. C. Lopes, Steven J. Ostro, Randolph L. Kirk, P. Paillou, Alexander G. Hayes, Jani Radebaugh, Jonathan I. Lunine, Ralph D. Lorenz, Giuseppe Mitri, Howard A. Zebker, Karl L. Mitchell, Ellen R. Stofan, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Department of Electrical Engineering [Stanford], Stanford University, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Sciences et Technologies - Bordeaux 1, Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Geological Sciences [BYU], Brigham Young University (BYU), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, and Proxemy Research Inc
Subjects: Planetary Sciences: Solid Surface Planets: Surface materials and properties, 010504 meteorology & atmospheric sciences, Atmospheric sciences, 01 natural sciences, Methane, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], chemistry.chemical_compound, symbols.namesake, Impact crater, 0103 physical sciences, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, Ejecta, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Hydrology, Life on Titan, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Atmospheric methane, Fossil fuel, Planetary Sciences: Solid Surface Planets: Remote sensing, Planetary Sciences: Solar System Objects: Titan, 1060), Geophysics, chemistry, 13. Climate action, Greenhouse gas, symbols, General Earth and Planetary Sciences, Titan (rocket family), business, Geology
Abstract: [1] Cassini RADAR observations now permit an initial assessment of the inventory of two classes, presumed to be organic, of Titan surface materials: polar lake liquids and equatorial dune sands. Several hundred lakes or seas have been observed, of which dozens are each estimated to contain more hydrocarbon liquid than the entire known oil and gas reserves on Earth. Dark dunes cover some 20% of Titan's surface, and comprise a volume of material several hundred times larger than Earth's coal reserves. Overall, however, the identified surface inventories (>3 × 104 km3 of liquid, and >2 × 105 km3 of dune sands) are small compared with estimated photochemical production on Titan over the age of the solar system. The sand volume is too large to be accounted for simply by erosion in observed river channels or ejecta from observed impact craters. The lakes are adequate in extent to buffer atmospheric methane against photolysis in the short term, but do not contain enough methane to sustain the atmosphere over geologic time. Unless frequent resupply from the interior buffers this greenhouse gas at exactly the right rate, dramatic climate change on Titan is likely in its past, present and future.
Published: 2008
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24. Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them

Author: Donald M. Reeves, Roger Soliva, Chris H. Okubo, Richard A. Schultz, Haakon Fossen, Department of Geological Sciences and Engineering [Reno], University of Nevada [Reno], Géosciences Montpellier, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Science [Bergen] (UiB), University of Bergen (UiB), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), and Desert Research Institute (DRI)
Subjects: Shearing (physics), [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, strike-slip faults, deformation bands, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, scaling, Geology, Geometry, Strain energy density function, Cataclastic rock, strain-energy density, 010502 geochemistry & geophysics, 01 natural sciences, Lodeve permian basin, Fracture toughness, Discontinuity (geotechnical engineering), Shear (geology), compaction bands, Deformation bands, Geotechnical engineering, Scaling, faulting, 0105 earth and related environmental sciences
Abstract: Displacement-length data from faults, joints, veins, igneous dikes, shear deformation bands, and compaction bands define two groups. The first group, having a power-law scaling relation with a slope of n = 1 and therefore a linear dependence of maximum displacement and discontinuity length (D-max = gamma L), comprises faults and shear (non-compactional or non-dilational) deformation bands. These shearing-mode structures, having shearing strains that predominate over volumetric strains across them, grow under conditions of constant driving stress, with the magnitude of near-tip stress on the same order as the rock's yield strength in shear. The second group, having a power-law scaling relation with a slope of n = 0.5 and therefore a dependence of maximum displacement on the square root of discontinuity length (D-max = alpha L-0.5), comprises joints, veins, igneous dikes, cataclastic deformation bands, and compaction bands. These opening- and closing-mode structures grow under conditions of constant fracture toughness, implying significant amplification of near-tip stress within a zone of small-scale yielding at the discontinuity tip. Volumetric changes accommodated by grain fragmentation, and thus control of propagation by the rock's fracture toughness, are associated with scaling of predominantly dilational and compactional structures with an exponent of n = 0.5.
Published: 2008
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25. Simulation of Na D emission near Europa during eclipse

Author: T. A. Cassidy, Robert E. Johnson, Paul E. Geissler, François Leblanc, Department of Astronomy [Charlottesville], University of Virginia [Charlottesville], US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and University of Virginia
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Europa atmosphere, Soil Science, Electron, Astrophysics, Aquatic Science, Oceanography, 01 natural sciences, Astrobiology, Physics::Geophysics, Atmosphere, Jupiter, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Eclipse, Physics, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Ecology, Wavelength range, Paleontology, Forestry, Torus, aurora, Wavelength, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract: [1] The Cassini imaging science subsystem observed Europa in eclipse during Cassini's Jupiter flyby. The disk-resolved observations revealed a spatially nonuniform emission in the wavelength range of 200–1050 nm (clear filters). By building on observations and simulations of Europa's Na atmosphere and torus we find that electron-excited Na in Europa's tenuous atmosphere can account for the observed emission if the Na is ejected preferentially from Europa's dark terrain.
Published: 2008
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26. Titan's diverse landscapes as evidenced by Cassini RADAR's third and fourth looks at Titan

Author: L. Roth, Y. Anderson, Rosaly M. C. Lopes, S. D. Wall, Bashar Rizk, R. Boehmer, William T. K. Johnson, Roberto Orosei, S. Hensley, Robert West, Bobby Kazeminejad, Yonggyu Gim, K. Kelleher, M. A. Janssen, Giorgio Franceschetti, Howard A. Zebker, G. Hamilton, Pierre Encrenaz, Laurence A. Soderblom, Roberto Seu, Flora Paganelli, S. Shaffer, Francesco Posa, Steven J. Ostro, Ralph D. Lorenz, Enrico Flamini, Randolph L. Kirk, Jani Radebaugh, Charles A. Wood, C. See, Charles Elachi, P. Paillou, Philip S. Callahan, Michael Allison, Jonathan I. Lunine, Lauren Wye, Elisabeth A. McFarlane, Ellen R. Stofan, S. Vetrella, Bryan Stiles, Giovanni Picardi, Duane O. Muhleman, Erich Karkoschka, Giovanni Alberti, Lunine, J. I., Elachi, C., Wall, S. D., Janssen, M. A., Allison, M. D., Anderson, Y., Boehmer, R., Callahan, P., Encrenaz, P., Flamini, E., Franceschetti, G., Gim, Y., Hamilton, G., Hensley, S., Johnson, W. T. K., Kelleher, K., Kirk, R. L., Lopes, R. M., Lorenz, R. D., Muhleman, D. O., Orosei, R., Ostro, S. J., Paganelli, F., Paillou, P., Picardi, G., Posa, F., Radebaugh, J., Roth, L. E., Seu, R., Shaffer, S., Soderblom, L. A., Stiles, B., Stofan, E. R., Vetrella, Sergio, West, R., Wood, C. A., Wye, L., Zebker, H., Alberti, G., Karkoschka, E., Rizk, B., Mcfarlane, E., See, C., Kazeminejad, B., Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Facoltá di Ingegneria, Facoltá di Ingegneria, Naples, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), CNR-IASF, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Sciences et Technologies - Bordeaux 1, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Dipartimento Interateneo di Fisica, Politecnico di Bari, Proxemy Research Inc, Planetary Science Institute [Tucson] (PSI), Stanford University, Department of Electrical Engineering [Stanford], CO.RI.S.T.A., European Space Department, Johns Hopkins University (JHU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Dept. Geological Sciences, and Brigham Young University (BYU)
Subjects: Synthetic aperture radar, 010504 meteorology & atmospheric sciences, Terrain, radar observations, surfaces, 01 natural sciences, law.invention, Latitude, Sand dune stabilization, Astrobiology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, Paleontology, geological processes, geophysics, satellites, titan, law, 0103 physical sciences, Radar, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Titan moon, Astronomy and Astrophysics, Crust, Tectonics, Radar imaging, Space and Planetary Science, Physical Sciences, symbols, Cassini, Titan (rocket family), Geology
Abstract: International audience; Cassini's third and fourth radar flybys, T7 and T8, covered diverse terrains in the high southern and equatorial latitudes, respectively. The T7 synthetic aperture radar (SAR) swath is somewhat more straightforward to understand in terms of a progressive poleward descent from a high, dissected, and partly hilly terrain down to a low flat plain with embayments and deposits suggestive of the past or even current presence of hydrocarbon liquids. The T8 swath is dominated by dunes likely made of organic solids, but also contain somewhat enigmatic, probably tectonic, features that may be partly buried or degraded by erosion or relaxation in a thin crust. The dark areas in T7 show no dune morphology, unlike the dark areas in T8, but are radiometrically warm like the dunes. The Huygens landing site lies on the edge of the T8 swath; correlation of the radar and Huygens DISR images allows accurate determination of its coordinates, and indicates that to the north of the landing site sit two large longitudinal dunes. Indeed, had the Huygens probe trajectory been just 10 km north of where it actually was, images of large sand dunes would have been returned in place of the fluvially dissected terrain actually seen?illustrating the strong diversity of Titan's landscapes even at local scales.
Published: 2008
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27. Varied Geologic Terrains at Titan's South Pole: First Results from T39

Author: STOFAN, E. R., ELACHI, C., LUNINE, J.I., LORENZ, R. D., KIRK, R. L., LOPES, R. M. C., WOOD, C. A., RADEBAUGH, J., WALL, S. D., MITCHELL, K. L., SODERBLOM, L. A., PAILLOU, Philippe, FARR, T., STILES, B., CALLAHAN, P., CASSINI RADAR TEAM, Proxemy Research Inc, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Wheeling Jesuit University, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: International audience; The Cassini RADAR pass T39 of the south polar region reveals extremely varied and in some cases complex surface morphologies, indicating that a range of geologic processes have operated, and are operating, in the region.
Published: 2008

28. Mapping and interpretation of Sinlap crater on Titan using Cassini VIMS and RADAR data

Author: Flora Paganelli, Pierre Encrenaz, Laurence A. Soderblom, Stéphane Le Mouélic, M. Crapeau, Sebastien Rodriguez, Robert H. Brown, Michael A. Janssen, Jason W. Barnes, Ralf Jaumann, Christophe Sotin, Gabriel Tobie, Roger N. Clark, S. D. Wall, Philippe Paillou, Dirk Geudtner, Kevin H. Baines, Bonnie J. Buratti, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Ames Research Center (ARC), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Denver], United States Geological Survey [Reston] (USGS), Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), DLR Institute of Planetary Research, German Aerospace Center (DLR), DLR Microwaves and Radar Institute, US Geological Survey [Flagstaff], University of Idaho [Moscow, USA], Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Planetary Science Institute [Tucson] (PSI), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institute of Geological Sciences [Berlin], Department of Earth Sciences [Berlin], and Free University of Berlin (FU)-Free University of Berlin (FU)
Subjects: Synthetic aperture radar, Atmospheric Science, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Institut für Planetenforschung, Soil Science, Mineralogy, Aquatic Science, Oceanography, Institut für Hochfrequenztechnik und Radarsysteme, 01 natural sciences, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Impact crater, Geochemistry and Petrology, law, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Panache, Radar, Ejecta, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Remote sensing, Ecology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Paleontology, Forestry, CASSINI, Plume, Planetengeologie, Geophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], symbols, Ejecta blanket, Satelliten-SAR-Systeme, Titan (rocket family), Geology
Abstract: International audience; Only a few impact craters have been unambiguously detected on Titan by the Cassini- Huygens mission. Among these, Sinlap is the only one that has been observed both by the RADAR and VIMS instruments. This paper describes observations at centimeter and infrared wavelengths which provide complementary information about the composition, 45 topography, and surface roughness. Several units appear in VIMS false color composites of band ratios in the Sinlap area, suggesting compositional heterogeneities. A bright pixel possibly related to a central peak does not show significant spectral variations, indicating either that the impact site was vertically homogeneous, or that this area has been recovered by homogeneous deposits. Both 50 VIMS ratio images and dielectric constant measurements suggest the presence of an area enriched in water ice around the main ejecta blanket. Since the Ku-band SAR may see subsurface structures at the meter scale, the difference between infrared and SAR observations can be explained by the presence of a thin layer transparent to the radar. An analogy with terrestrial craters in Libya supports this interpretation. Finally, a tentative model describes the geological 55 history of this area prior, during, and after the impact. It involves mainly the creation of ballistic ejecta and an expanding plume of vapor triggered by the impact, followed by the redeposition of icy spherules recondensed from this vapor plume blown downwind. Subsequent evolution is then driven by erosional processes and aeolian deposition.
Published: 2008
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29. Dunes on Titan observed by Cassini Radar

Author: J. Radebaugh, R.D. Lorenz, J.I. Lunine, S.D. Wall, G. Boubin, E. Reffet, R.L. Kirk, R.M. Lopes, E.R. Stofan, L. Soderblom, M. Allison, M. Janssen, P. Paillou, P. Callahan, C. Spencer, null the Cassini Radar Team, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Department of Geological Sciences [BYU], Brigham Young University (BYU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Therapies Interventionnelles Assistees Par l'Image et la Simulation, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Droit et Santé, Proxemy Research Inc, US Geological Survey [Denver], Departement of Geology, Tulane University, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Department of Clinical Chemistry, Academic Medical Center - Academisch Medisch Centrum [Amsterdam] (AMC), University of Amsterdam [Amsterdam] (UvA)-University of Amsterdam [Amsterdam] (UvA), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), SLAC National Accelerator Laboratory (SLAC), and Stanford University
Subjects: 010504 meteorology & atmospheric sciences, Equator, surfaces, Atmospheric sciences, 01 natural sciences, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, satellites, law, High latitude, 0103 physical sciences, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Landform, Sediment, Astronomy and Astrophysics, Wind direction, Saturn, 13. Climate action, Space and Planetary Science, symbols, Aeolian processes, Titan (rocket family), Titan, Geology
Abstract: International audience; Thousands of longitudinal dunes have recently been discovered by the Titan Radar Mapper on the surface of Titan. These are found mainly within ±30° of the equator in optically-, near-infrared-, and radar-dark regions, indicating a strong proportion of organics, and cover well over 5% of Titan's surface. Their longitudinal duneform, interactions with topography, and correlation with other aeolian forms indicate a single, dominant wind direction aligned with the dune axis plus lesser, off-axis or seasonally alternating winds. Global compilations of dune orientations reveal the mean wind direction is dominantly eastwards, with regional and local variations where winds are diverted around topographically high features, such as mountain blocks or broad landforms. Global winds may carry sediments from high latitude regions to equatorial regions, where relatively drier conditions prevail, and the particles are reworked into dunes, perhaps on timescales of thousands to tens of thousands of years. On Titan, adequate sediment supply, sufficient wind, and the absence of sediment carriage and trapping by fluids are the dominant factors in the presence of dunes.
Published: 2008
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30. Different appearance of Titan's dunes

Author: PAGANELLI, F., CALLAHAN, P., HENSLEY, S., LORENZ, R., LUNINE, J., KIRK, R., STILES, B., GIM, Y., WEST, R., JANSSEN, M., LOPES, R., STOFAN, E., WALL, S., PAILLOU, Philippe, RADEBAUGH, J., THE CASSINI RADAR TEAM, A., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Proxemy Research Inc, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 6281 Titan
Abstract: In this paper we analyze Cassini's Titan Radar Mapper recent flybys and yet more evidence of dark linear dunes, in the latitude between 30° S and 30° N, whose orientations are somewhat comparable to previous dune observations but at closer study show morphological differences. The appearance of Titan's dunes depends on the projected look direction of the Cassini Radar antenna, incidence angle and resolution. Dune fields are generally oriented East/West on Titan, and for many radar observations the flyby is in the equatorial plane. At closest approach the imaging direction is most nearly normal to the dune direction such as in the central portion of the T8 swath. Away from that configuration, and especially past the -/+10 minutes from close approach, the relative azimuth angle that the projected look direction of the Cassini Radar antenna has with respect to the surface changes rapidly along with incidence angle and resolution resulting in signal attenuation of the imaged features. Observational biases in the SAR images are key for dunes comparison across Titan's equatorial belt. The results show that in some regions the projected look direction could be on the order of 60° and parallel to the long axis of the radar dark features direction (i.e. T16, T25, T28), therefore suggesting that the variation in backscatter must be a combination of compositional dunes dark material and bright interdune material, varying roughness and topography when present. This suggests that we cannot assume that all the dune fields currently imaged can be characterized simply on the bases of their orientation and therefore we suggest that the characterization of the imaged surface features should be divided into at least two categories: -1) topography driven (in which Radar-clinometry can be applied); -2) compositional or due to varying roughness.
Published: 2008

31. The north polar lakes of Titan as observed by Cassini Radar

Author: MITCHELL, K. L., PAILLOU, Philippe, KIRK, R. L., LUNINE, J.I., STOFAN, E. R., RADEBAUGH, J., WALL, S. D., HAYES, A. G., LOPES, R. M., STILES, B. W., OSTRO, S. J., LORENZ, R. D., WOOD, C. A., CASSINI RADAR TEAM, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Proxemy Research Inc, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), and Wheeling Jesuit University
Subjects: 9345 Large bodies of water (e.g, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 2419 Ion chemistry and composition (0335), 2400 IONOSPHERE (6929), lakes and inland seas) (0746)
Abstract: Over the course of a year, Cassini RADAR obtained Synthetic Aperture Radar images covering 69 percent of Titan's polar region north of 65 degrees; the region being 1.4E6 km3 in extent, greater than double the land area of the USA. We observe several hundred lakes with a range of morphological expression, including areally massive and morphologically distinctive "seas", covering ~15% of the polar region. Lakes are extremely radar dark, consistent with a lossy liquid hydrocarbon. Preliminary laboratory estimates suggest that loss tangents in the range 10E4 to 2x10E3 are reasonable, which implies that one can see through at least a few to many tens of m of liquids before the noise floor is reached, consistent with observed brightening towards many lake shores. North polar lake volumes are most likely in the 8E3 - 1.4E6 km3 range. Uncertainties will be reduced as more data, both image-based and experimental, are obtained but we can conclude with a high degree of confidence that hydrocarbon lakes on Titan are more voluminous than known terrestrial oil reserves; current estimates range from 2248 - 3896 billion barrels of oil (J. Hakes, 2000, Long Term World Oil Supply, Meeting of the Am. Ass. Pet. Geol., 18th April 2000, New Orleans, LA, http://www.eia.doe.gov/pub/oil_gas/petroleum/presentations/2000/long_term_supply.), hence 357 - 619 km3 . Small lakes often occupy steep-sided depressions, and although thermal and cryovolcanic origins cannot be completely ruled out, we are seeing growing geomorphologic evidence for dissolution chemistry, indicative of karst-like geology. The dichotomy between small lakes over slightly more than one half of the region, and seas on the other half, may be best explained by a topographic anomaly causing sub-surface flow of materials from the lakes to the seas. This may also explain observations by the Cassini ISS team (E. Turtle et al., in prep.) of a putative massive sea extending considerably further south than other observed north polar lakes.
Published: 2007

32. Titan's North Polar Lakes as Observed by Cassini Radar: An Update

Author: MITCHELL, K. L., WALL, S. D., STOFAN, E. R., LOPES, R. M. C., JANSSEN, M., STILES, B., PAILLOU, Philippe, MITRI, G., LUNINE, J., OSTRO, S., LORENZ, R. D., FARR, T. G., KIRK, R. L., RADEBAUGH, J., CASSINI RADAR SCIENCE TEAM, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Proxemy Research Inc, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), US Geological Survey [Flagstaff], and United States Geological Survey [Reston] (USGS)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Not Available
Published: 2007

33. Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006

Author: P. Kenneth Seidelmann, Brent A. Archinal, Philip J. Stooke, J. L. Hilton, David J. Tholen, Iwan P. Williams, Guy J. Consolmagno, Michael F. A'Hearn, Daniel Hestroffer, Juergen Oberst, G. A. Krasinsky, Al Conrad, Peter C. Thomas, E. F. Tedesco, Gregory A. Neumann, University of Virginia, US Geological Survey, Flagstaff, University of Maryland, W. M. Keck Observatory, Vatican Observatory, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, United States Naval Observatory (USNO), Institute of Applied Astronomy, NASA/Goddard Space Flight Center (NASA/GSFC), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Physics and Astronomy, University of Western Ontario, University of New Hampshire (UNH), University of Hawaii, Hilo, Department of Astronomy, Cornell University, and Queen Mary University of London, Mile End Road
Subjects: Astrophysics and Astronomy, Satellites, Planets, Rotation, Rotation periods, Jupiter, Group (periodic table), Planet, Saturn, Comets, Mathematical Physics, Physics, Geography, Applied Mathematics, Minor planets, Astronomy and Astrophysics, Travel time, Pluto, Computational Mathematics, Asteroid, Space and Planetary Science, Modeling and Simulation, Physics::Space Physics, Rotation axes, Sizes, Astrophysics::Earth and Planetary Astrophysics, Shapes, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Cartographic coordinates, Cartography
Abstract: International audience; Every three years the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report introduces improved values for the pole and rotation rate of Pluto, Charon, and Phoebe, the pole of Jupiter, the sizes and shapes of Saturn satellites and Charon, and the poles, rotation rates, and sizes of some minor planets and comets. A high precision realization for the pole and rotation rate of the Moon is provided. The expression for the Sun's rotation has been changed to be consistent with the planets and to account for light travel time
Published: 2007
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34. The lakes of Titan

Author: Pierre Encrenaz, S. Hensley, G. Hamilton, Steven J. Ostro, Randolph L. Kirk, Michael Janssen, Rosaly M. C. Lopes, Philip S. Callahan, Yonggyu Gim, Roberto Seu, E. Flamini, R. D. Lorenz, K. Kelleher, Giovanni Picardi, Duane O. Muhleman, L. Roth, Matthew A. Allison, Y. Anderson, Howard A. Zebker, William T. K. Johnson, Jani Radebaugh, Francesco Posa, Laurence A. Soderblom, Charles A. Wood, Lauren Wye, Bryan Stiles, Jonathan I. Lunine, R. Boehmer, G. Francescetti, S. Shaffer, P. Paillou, Charles Elachi, Karl L. Mitchell, Flora Paganelli, Robert West, S. Vetrella, Ellen R. Stofan, S. D. Wall, Proxemy Research Inc, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Wheeling Jesuit University, Department of Electrical Engineering [Stanford], Stanford University, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Alenia Aerospazio, Facoltá di Ingegneria, Facoltá di Ingegneria, Naples, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Dipartimento Interateneo di Fisica, Politecnico di Bari, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], E. R., Stofan, C., Elachi, J. I., Lunine, R. D., Lorenz, B., Stile, K. L., Mitchell, S., Ostro, L., Soderblom, C., Wood, H., Zebker, S., Wall, M., Janssen, R., Kirk, R., Lope, F., Paganelli, J., Radebaugh, L., Wye, Y., Anderson, M., Allison, R., Boehmer, P., Callahan, P., Encrenaz, E., Flamini, Franceschetti, Giorgio, Y., Gim, G., Hamilton, S., Hensley, W. T. K., Johnson, K., Kelleher, D., Muhleman, P., Paillou, G., Picardi, F., Posa, L., Roth, R., Seu, S., Shaffer, Vetrella, Sergio, and R., West
Subjects: Haze, 010504 meteorology & atmospheric sciences, Atmospheric sciences, 01 natural sciences, Methane, Astrobiology, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], chemistry.chemical_compound, symbols.namesake, law, Radar imaging, 0103 physical sciences, Radar, Water cycle, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Life on Titan, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Northern Hemisphere, Radar Imaging, Titan moon, chemistry, 13. Climate action, symbols, Cassini, Titan (rocket family), Geology
Abstract: The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface1, 2. Initial visible3 and radar4, 5 imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface5, 6. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70° north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface2, 7. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.
Published: 2007
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35. The Lakes and Seas of Titan

Author: Howard A. Zebker, Michael Janssen, Rosaly M. C. Lopes, Charles A. Wood, Stephen D. Wall, Ralph D. Lorenz, Flora Paganelli, Jonathan I. Lunine, P. Paillou, Alexander Hayes, Jani Radebaugh, Steven J. Ostro, Randolph L. Kirk, Giuseppe Mitri, Karl L. Mitchell, Ellen R. Stofan, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Proxemy Research Inc, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Wheeling Jesuit University, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Electrical Engineering [Stanford], and Stanford University
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Earth science, Atmospheric methane, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars Exploration Program, 01 natural sciences, Methane, Astrobiology, Planetary Sciences: Solar System Objects: Titan, symbols.namesake, chemistry.chemical_compound, chemistry, Planetary Sciences: Solar System Objects: Saturnian satellites, 13. Climate action, 0103 physical sciences, symbols, General Earth and Planetary Sciences, Water cycle, Planetary Sciences: Solar System Objects: General or miscellaneous, Titan (rocket family), 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; The study of Titan, Saturn's largest satellite, is a major goal of the Cassini-Huygens mission. This joint project between NASA, the European Space Agency, and the Italian Space Agency consists of a Saturn orbiter (Cassini) and a Titan probe (Huygens). Since the mission's arrival at Saturn in July 2004, one of its most spectacular discoveries has been the finding of the first extraterrestrial nonmagmatic standing bodies of liquid: Titan's hydrocarbon lakes and seas. In July 2006, the first synthetic aperture radar (SAR) images of Titan's north polar region btained by the Cassini spacecraft showed dozens of lakes above latitudes of 70° [Stofan et al., 2007]. Subsequent SAR images obtained by Cassini have covered approximately 68% of Titan's north polar region at latitudes above 60 degrees. These images show more than 400 radar-dark areas that we interpret as being liquid lakes (shown in dark blue in Figure 1), including a few that are so large that they rightfully may be called seas. We discuss here the evidence for liquids on Titan, the distribution and morphology of lakes, and recent data that indicate the presence of lakes in the south polar regions.
Published: 2007
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36. Composition and Physical Properties of Enceladus' Surface

Author: Christophe Sotin, Priscilla Cerroni, Dennis L. Matson, Jason W. Barnes, P. D. Nicholson, Dale P. Cruikshank, Ralf Jaumann, Bruno Sicardy, Giancarlo Bellucci, Robert M. Nelson, Bonnie J. Buratti, Thomas B. McCord, S. Newman, R. N. Clark, James M. Bauer, Yves Langevin, M. Combes, Vittorio Formisano, Pierre Drossart, Robert H. Brown, Rachel Mastrapa, Kevin H. Baines, Tom Momary, Fabrizio Capaccioni, Angioletta Coradini, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, US Geological Survey, Flagstaff, Jet Propulsion Laboratory, California Institute of Technology (JPL), SETI Institute, NASA Ames Research Center, Moffett Field, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Instituto di Astrofisica Spaziale - CNR, Area della recerca di Tor Vergata, Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Department of Earth and Space Sciences, University of Washington, Department of Astronomy, Cornell University, and Université de Nantes (UN)
Subjects: Surface (mathematics), Materials science, Extraterrestrial Environment, Spectrophotometry, Infrared, 010504 meteorology & atmospheric sciences, Infrared, Saturnian satellites, 01 natural sciences, Astrobiology, Enceladus, Ammonia, 0103 physical sciences, VIMS, Ice Cover, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Spectrometer, Atmosphere, Ice, surface composition, Carbon Dioxide, Amorphous solid, Satellites de Glace, Saturn, 13. Climate action, Cassini, Satellite, Water ice, Atmospheric column, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Observations of Saturn's satellite Enceladus using Cassini's Visual and Infrared Mapping Spectrometer instrument were obtained during three flybys of Enceladus in 2005. Enceladus' surface is composed mostly of nearly pure water ice except near its south pole, where there are light organics, CO 2 , and amorphous and crystalline water ice, particularly in the region dubbed the âtiger stripes.â An upper limit of 5 precipitable nanometers is derived for CO in the atmospheric column above Enceladus, and 2% for NH 3 in global surface deposits. Upper limits of 140 kelvin (for a filled pixel) are derived for the temperatures in the tiger stripes.
Published: 2006
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37. The Lakes of Titan

Author: Lunine, J., Stofan, E., Elachi, C., Lorenz, R., Stiles, B., Mitchell, K. L., Ostro, S., Soderblom, L., Wood, C., Zebker, H., Wall, S., Janssen, M., Kirk, R., Lopes, R., Paganelli, F., Radebaugh, J., Wye, L., Callahan, P., Anderson, Y., Allison, M., Boehmer, R., Encrenaz, P., Flamini, E., Franceschetti, G., Gim, Y., Hamilton, G., Hensely, S., Johnson, W. T., Kelleher, K., Muhleman, D., Paillou, Philippe, Picardi, G., Posa, F., Roth, L., Seu, R., Shaffer, S., Vetrella, S., West, R., Orosei, R., Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Proxemy Research Inc, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Wheeling Jesuit University, Department of Electrical Engineering [Stanford], Stanford University, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Alenia Aerospazio, Facoltá di Ingegneria, Facoltá di Ingegneria, Naples, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Dipartimento INFOCOM [Roma], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Dipartimento Interateneo di Fisica, Politecnico di Bari, CNR-IASF, École normale supérieure - Paris (ENS Paris), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], and Pomies, Marie-Paule
Subjects: [PHYS.ASTR.EP] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 5419 Hydrology and fluvial processes, 5470 Surface materials and properties, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 5225 Early environment of Earth, 6281 Titan, 5462 Polar regions
Abstract: The Cassini Radar flyby of Saturn's moon Titan on 22 July 2006 (T16) provides compelling evidence for the presence of liquid lakes on the surface of Titan. The radar images polewards of 70°N show over 75 circular to irregular radar dark patches from 3 km to over 170 km across, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. Some patches are uniformly dark in appearance, with no measureable echo, while others vary in brightness. We interpret these as lakes based on their very low radar reflectivity and morphological similarities to lakes, including associated channels, location in topographic depressions and multiple shorelines. Lakes appear in a number of apparent states, including fully drained, partially dry and liquid-filled. These northern hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface `liquid methane' table.
Published: 2006

38. Investigation of the Sinlap Crater on Titan Using VIMS and RADAR Data

Author: Le Mouélic, S., Paillou, Philippe, Rodriguez, S., Crapeau, M., Sotin, C., Hirtzig, M., Brown, R. H., Soderblom, L. A., Clark, R. N., Buratti, B. J., Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), US Geological Survey [Denver], Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NASA-California Institute of Technology (CALTECH), and Pomies, Marie-Paule
Subjects: [PHYS.ASTR.EP] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 6297 Instruments and techniques, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 6281 Titan, 6094 Instruments and techniques
Abstract: Poster; Few impact craters have been observed so far on Titan by the CASSINI orbiter. A 80 km diameter crater (called Sinlap) has been observed by all three imaging instruments (ISS, VIMS and Radar). Observations at infrared and radar wavelengths provide very complementary information on the composition, topography and surface roughness of the surface materials. We first investigate the spectral characteristics of the Sinlap area using VIMS data, in order to map the spectral heterogeneities, highlighting the different compositional and physical characteristics of the materials excavated by the impact. These units are then compared to the radar observations acquired at T3. The differences between optical and radar properties are discussed in terms of composition and vertical heterogeneity
Published: 2006

39. Titan radar mapper observations from Cassini's T3 fly-by

Author: Pierre Encrenaz, Scott Hensley, William L. Johnson, Ellen R. Stofan, Roberto Seu, R. Boehmer, Steven J. Ostro, Randolph L. Kirk, Rosaly M. C. Lopes, K. Kelleher, Flora Paganelli, Matthew A. Allison, S. Vetrella, E. Flamini, Francesco Posa, G. Francescetti, G. Hamilton, Robert West, Laurence A. Soderblom, Charles A. Wood, Philip S. Callahan, Ralph D. Lorenz, Charles Elachi, S. D. Wall, S. Shaffer, Howard A. Zebker, M. A. Janssen, Bryan Stiles, Yonggyu Gim, L. Roth, Y. Anderson, Giovanni Picardi, Duane O. Muhleman, Jonathan I. Lunine, Lauren Wye, C., Elachi, S., Wall, M., Janssen, E., Stofan, R., Lope, R., Kirk, R., Lorenz, J., Lunine, F., Paganelli, L., Soderblom, C., Wood, L., Wye, H., Zebker, Y., Anderson, S., Ostro, M., Allison, R., Boehmer, P., Callahan, P., Encrenaz, E., Flamini, Franceschetti, Giorgio, Y., Gim, G., Hamilton, S., Hensley, W., Johnson, K., Kelleher, D., Muhleman, G., Picardi, F., Posa, L., Roth, R., Seu, S., Shaffer, B., Stile, Vetrella, Sergio, R., West, Jet Propulsion Laboratory, California Institute of Technology (JPL), Proxemy Research, Bowie, US Geological Survey, Flagstaff, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Planetary Science Institute, Tucson, Stanford University, Goddard Institute for Space Studies, National Aeronautics and Space Administration New York, Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Alenia Aerospazio, Facoltá di Ingegneria, Geological and Planetary Sciences, California Institute of Technology, Pasadena, Universitá La Sapienza, and INFM and Dipartimento Interateneo di Fisica
Subjects: Synthetic aperture radar, geography, Multidisciplinary, geography.geographical_feature_category, Landform, Fluvial, Titan moon, Space-based radar, law.invention, Astrobiology, symbols.namesake, Impact crater, law, symbols, Radiometry, Cassini, Radar Mapper, Radar, Titan (rocket family), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Remote sensing
Abstract: International audience; Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity.
Published: 2006
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40. A Different Look At Titans Dunes

Author: PAGANELLI, Flora, CALLAHAN, P., HENSLEY, S., LORENZ, R., LUNINE, J., KIRK, R., STILES, B., JANSSEN, M., LOPES, R., STOFAN, E., WALL, S., PAILLOU, Philippe, THE RADAR TEAM, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Proxemy Research Inc, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: International audience; In its six Titan flybys (T16: July 2006) the Cassini's Titan Radar Mapper has imaged yet again more evidence of dark linear streaks and/or dunes. The latitude, between 14-25 N, and orientation of these features is comparable to the one seen in the T3 (February 2005) Titan flyby. The implications of these new observation stand on the particular geometry in which the dunes have been imaged in the radar swath and consequently on the effect that this has on their characterization. Previous flyby geometries had look direction perpendicular to the general azimuth of the dunes, thus allowing identification of dunes with generally observed E-W orientation (see also Radebaugh et al., this conference) and --because of the favorable geometry -- to identify their topographic expression. T16 has shown that the same dark linear streaks and/or dunes trend can be imaged with look direction quasi-parallel to them, very similar to the + 25 E-W azimuth in T3. This has the implication that these features might be superposed streaks with none or minimal topography, and that they are visible because of differential erosion between the radar bright rougher substrate and the radar dark of fine particle smooth surface deposits. This paper will asses the imaging geometry at which these dark linear streaks and/or dunes are seen in T16 and T3 flybys, and what the data are telling us in terms of their physical and morphological properties.
Published: 2006

41. The evolution of Titan's mid-latitude clouds

Author: Vito Mennella, B. J. Buratti, Jason W. Barnes, Yves Langevin, Roger N. Clark, Paulo Penteado, Dale P. Cruikshank, Ralf Jaumann, Robert M. Nelson, Robert H. Brown, L. A. Soderblom, Giancarlo Bellucci, J. P. Bibring, M. Combes, Christophe Sotin, Fabrizio Capaccioni, R. Kursinski, Priscilla Cerroni, T. B. McCord, Vittorio Formisano, Pierre Drossart, Bruno Sicardy, Angioletta Coradini, P. D. Nicholson, Caitlin A. Griffith, Kevin H. Baines, Douglas M. Matson, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Jet Propulsion Laboratory, California Institute of Technology (JPL), Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), US Geological Survey, Flagstaff, SETI Institute, NASA Ames Research Center, Moffett Field, Institute for Planetary Exploration, Deutsches Zentrum for Luft und Raumfahrt, Department of Earth and Space Sciences, University of Washington, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), and Department of Astronomy, Cornell University
Subjects: 010504 meteorology & atmospheric sciences, Meteorology, Extraterrestrial Environment, Infrared, clouds, Atmospheric sciences, 01 natural sciences, Troposphere, symbols.namesake, 0103 physical sciences, VIMS, Spacecraft, 010303 astronomy & astrophysics, Optical depth, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Multidisciplinary, Spectrometer, Atmosphere, Spectrum Analysis, Satellites de Glace, Saturn, 13. Climate action, Middle latitudes, symbols, Cassini, Titan, Titan (rocket family), Longitude, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Methane, Geology
Abstract: International audience; Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal that the horizontal structure, height, and optical depth of Titan's clouds are highly dynamic. Vigorous cloud centers are seen to rise from the middle to the upper troposphere within 30 minutes and dissipate within the next hour. Their development indicates that Titan's clouds evolve convectively; dissipate through rain; and, over the next several hours, waft downwind to achieve their great longitude extents. These and other characteristics suggest that temperate clouds originate from circulation-induced convergence, in addition to a forcing at the surface associated with Saturn's tides, geology, and/or surface composition.
Published: 2005
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42. The Atmospheres of Saturn and Titan in the Near-Infrared First Results of Cassini/vims

Author: Kevin H. Baines, Roger N. Clark, Yves Langevin, Giancarlo Bellucci, Vittorio Formisano, Fabrizio Capaccioni, P. D. Nicholson, V. Mennella, Angioletta Coradini, D. P. Cruikshank, Robert M. Nelson, Caitlin A. Griffith, Robert H. Brown, T. B. McCord, C. Sotin, M. Combes, Jean-Pierre Bibring, B. J. Buratti, Tom Momary, Dennis L. Matson, Priscilla Cerroni, Pierre Drossart, R. Jaumann, Bruno Sicardy, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory, California Institute of Technology (JPL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), US Geological Survey, Flagstaff, Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), SETI Institute, NASA Ames Research Center, Moffett Field, Department of Planetary Exploration, DLR, Department of Earth and Space Sciences, University of Washington, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), and Department of Astronomy, Cornell University
Subjects: Haze, 010504 meteorology & atmospheric sciences, Atmospheric sciences, 01 natural sciences, law.invention, Troposphere, Atmosphere, symbols.namesake, Orbiter, Planet, law, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Near-Infrared, VIMS, Atmosphere of Titan, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Astronomy, Astronomy and Astrophysics, Satellites de Glace, Planetary science, Saturn, 13. Climate action, Space and Planetary Science, symbols, Cassini, Titan (rocket family), Titan, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: International audience; The wide spectral coverage and extensive spatial, temporal, and phase-angle mapping capabilities of the Visual Infrared Mapping Spectrometer (VIMS) onboard the Cassini-Huygens Orbiter are producing fundamental new insights into the nature of the atmospheres of Saturn and Titan. For both bodies, VIMS maps over time and solar phase angles provide information for a multitude of atmospheric constituents and aerosol layers, providing new insights into atmospheric structure and dynamical and chemical processes. For Saturn, salient early results include evidence for phosphine depletion in relatively dark and less cloudy belts at temperate and mid-latitudes compared to the relatively bright and cloudier Equatorial Region, consistent with traditional theories of belts being regions of relative downwelling. Additional Saturn results include (1) the mapping of enhanced trace gas absorptions at the south pole, and (2) the first high phase-angle, high-spatial-resolution imagery of CH4 fluorescence. An additional fundamental new result is the first nighttime near-infrared mapping of Saturn, clearly showing discrete meteorological features relatively deep in the atmosphere beneath the planet's sunlit haze and cloud layers, thus revealing a new dynamical regime at depth where vertical dynamics is relatively more important than zonal dynamics in determining cloud morphology. Zonal wind measurements at deeper levels than previously available are achieved by tracking these features over multiple days, thereby providing measurements of zonal wind shears within Saturn's troposphere when compared to cloudtop movements measured in reflected sunlight. For Titan, initial results include (1) the first detection and mapping of thermal emission spectra of CO, CO2, and CH3D on Titan's nightside limb, (2) the mapping of CH4 fluorescence over the dayside bright limb, extending to ˜ ˜750 km altitude, (3) wind measurements of ˜ ˜0.5 ms-1, favoring prograde, from the movement of a persistent (multiple months) south polar cloud near 88° S latitude, and (4) the imaging of two transient mid-southern-latitude cloud features.
Published: 2005
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43. A 5-Micron-Bright Spot on Titan: Evidence for Surface Diversity

Author: Roger N. Clark, Michael E. Brown, Dale P. Cruikshank, Emily L. Schaller, Jason Perry, Angioletta Coradini, Thomas B. McCord, Alfred S. McEwen, Jason W. Barnes, Elizabeth P. Turtle, Bonnie J. Buratti, Robert H. Brown, Michael Janssen, Yves Langevin, J. Barbara, Henry G. Roe, P. D. Nicholson, Giancarlo Bellucci, Caitlin A. Griffith, Ralf Jaumann, Jean-Pierre Bibring, S. Fussner, Richard West, Christophe Sotin, Vittorio Formisano, Dennis L. Matson, Bruno Sicardy, M. Combes, Kevin H. Baines, Ralph D. Lorenz, Charles Elachi, Pierre Drossart, Fabrizio Capaccioni, A. H. Bouchez, Priscilla Cerroni, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Jet Propulsion Laboratory, California Institute of Technology (JPL), Geological and Planetary Sciences, California Institute of Technology, Pasadena, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), US Geological Survey, Flagstaff, NASA Goddard Institute for Space Studies, Columbia University, W. M. Keck Observatory, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), SETI Institute, NASA Ames Research Center, Moffett Field, Institute for Planetary Exploration, Deutsches Zentrum for Luft und Raumfahrt, Department of Earth and Space Sciences, University of Washington, and Department of Astronomy, Cornell University
Subjects: Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Infrared, 01 natural sciences, Albedo feature, symbols.namesake, Optics, Dry Ice, 0103 physical sciences, VIMS, Geophysical Phenomena, Imaging science, Spacecraft, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Multidisciplinary, Spectrometer, Atmosphere, business.industry, Spectrum Analysis, Ice, Temperature, Water, Astronomy, Wavelength, Satellites de Glace, Saturn, Bright spot, infrared, symbols, Cassini, Titan, business, Titan (rocket family), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Methane, Geology
Abstract: International audience; Observations from the Cassini Visual and Infrared Mapping Spectrometer show an anomalously bright spot on Titan located at 80°W and 20°S. This area is bright in reflected light at all observed wavelengths, but is most noticeable at 5 microns. The spot is associated with a surface albedo feature identified in images taken by the Cassini Imaging Science Subsystem. We discuss various hypotheses about the source of the spot, reaching the conclusion that the spot is probably due to variation in surface composition, perhaps associated with recent geophysical phenomena.
Published: 2005
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44. Calibration of numerical models for small debris flows in Yosemite Valley, California, USA

Author: Bertolo, P., Wieczorek, G. F., EGU, Publication, DITAG (Dept of Land, US Geological Survey [Flagstaff], and United States Geological Survey [Reston] (USGS)
Subjects: lcsh:GE1-350, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:QE1-996.5, lcsh:Geography. Anthropology. Recreation, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, lcsh:TD1-1066, [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment, lcsh:Geology, lcsh:G, [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, lcsh:Environmental technology. Sanitary engineering, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, lcsh:Environmental sciences
Abstract: International audience; This study compares documented debris flow runout distances with numerical simulations in the Yosemite Valley of California, USA, where about 15% of historical events of slope instability can be classified as debris flows and debris slides (Wieczorek and Snyder, 2004). To model debris flows in the Yosemite Valley, we selected six streams with evidence of historical debris flows; three of the debris flow deposits have single channels, and the other three split their pattern in the fan area into two or more channels. From field observations all of the debris flows involved coarse material, with only very small clay content. We applied the one dimensional DAN (Dynamic ANalysis) model (Hungr, 1995) and the two-dimensional FLO-2D model (O'Brien et al., 1993) to predict and compare the runout distance and the velocity of the debris flows observed in the study area. As a first step, we calibrated the parameters for the two softwares through the back analysis of three debris- flows channels using a trial-and-error procedure starting with values suggested in the literature. In the second step we applied the selected values to the other channels, in order to evaluate their predictive capabilities. After parameter calibration using three debris flows we obtained results similar to field observations We also obtained a good agreement between the two models for velocities. Both models are strongly influenced by topography: we used the 30 m cell size DTM available for the study area, that is probably not accurate enough for a highly detailed analysis, but it can be sufficient for a first screening.
Published: 2005

45. Cassini radar views the surface of Titan

Author: S. Vetrella, M. A. Janssen, L. Roth, Y. Anderson, Giovanni Picardi, Pierre Encrenaz, Duane O. Muhleman, Lauren Wye, Scott Hensley, Howard A. Zebker, Robert West, Laurence A. Soderblom, Roberto Seu, Enrico Flamini, S. D. Wall, Jonathan I. Lunine, Ellen R. Stofan, S. Shaffer, K. Kelleher, Matthew A. Allison, Yonggyu Gim, Philip S. Callahan, G. Hamilton, Rosaly M. C. Lopes, Giorgio Franceschetti, R. Boehmer, Francesco Posa, Charles A. Wood, William L. Johnson, Flora Paganelli, Steven J. Ostro, Randolph L. Kirk, Bryan Stiles, Ralph D. Lorenz, Charles Elachi, Elachi, C., Wall, S., Anderson, Y., Boehmer, R., Callahan, P., Encrenaz, P., Flamini, E., Franceschetti, Giorgio, Gim, Y., Hamilton, G., Hensley, S., Janssen, M., Johnson, W., Kelleher, K., Kirk, R., Lopes, R., Lorenz, R., Lunine, J., Muhleman, D., Ostro, S., Paganelli, F., Picardi, G., Posa, F., Roth, L., Seu, R., Shaffer, S., Soderblom, L., Stiles, B., Stofan, E., Vetrella, Sergio, West, R., Wood, C., Wye, L., Zebker, H., Jet Propulsion Laboratory, California Institute of Technology (JPL), Goddard Institute for Space Studies, National Aeronautics and Space Administration New York, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Agenzia Spaziale Italiana (ASI), Facoltá di Ingegneria, US Geological Survey, Flagstaff, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Geological and Planetary Sciences, California Institute of Technology, Pasadena, Universitá La Sapienza, INFM and Dipartimento Interateneo di Fisica, Proxemy Research, Laytonsville, Planetary Science Institute, Tucson, and Stanford University
Subjects: Brightness, Extraterrestrial Environment, Volcanic Eruptions, law.invention, Atmosphere, symbols.namesake, Impact crater, law, Radar imaging, Emissivity, Radar, Organic Chemicals, Spacecraft, Remote sensing, Multidisciplinary, Ice, Temperature, Hydrocarbons, Saturn, Brightness temperature, symbols, Cassini, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Titan (rocket family), Titan, Geology, radar
Abstract: International audience; The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of ~0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.
Published: 2005
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46. Principal components analysis of Jupiter VIMS spectra

Author: Ralf Jaumann, Yves Langevin, Bruno Sicardy, G. Hansen, P. D. Nicholson, Thomas B. McCord, Bonnie J. Buratti, Christophe Sotin, M.C. Chamberlain, Roger N. Clark, Vittorio Formisano, Jean-Pierre Bibring, Kevin H. Baines, Robert M. Nelson, Gianrico Filacchione, Mark R. Showalter, Priscilla Cerroni, Pierre Drossart, Emiliano D'Aversa, K. Hibbits, Giancarlo Bellucci, Robert H. Brown, Dennis L. Matson, Dale P. Cruikshank, Vito Mennella, Fabrizio Capaccioni, Angioletta Coradini, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Jet Propulsion Laboratory, California Institute of Technology (JPL), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), US Geological Survey, Flagstaff, SETI Institute, NASA Ames Research Center, Moffett Field, Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Planetary Exploration, DLR, Department of Earth and Space Sciences, University of Washington, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), and Department of Astronomy, Cornell University
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Spectrometer, Channel (digital image), Wavelength range, Aerospace Engineering, Astronomy and Astrophysics, Stellar classification, 01 natural sciences, Spectral line, Jupiter, Satellites de Glace, Geophysics, Space and Planetary Science, 0103 physical sciences, Principal component analysis, General Earth and Planetary Sciences, Great Red Spot, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Remote sensing
Abstract: International audience; During Cassini - Jupiter flyby occurred in December 2000, Visual-Infrared mapping spectrometer (VIMS) instrument took several image cubes of Jupiter at different phase angles and distances. We have analysed the spectral images acquired by the VIMS visual channel by means of a principal component analysis technique (PCA). The original data set consists of 96 spectral images in the 0.35-1.05 mum wavelength range. The product of the analysis are new PC bands, which contain all the spectral variance of the original data. These new components have been used to produce a map of Jupiter made of seven coherent spectral classes. The map confirms previously published work done on the Great Red Spot by using NIMS data. Some other new findings, presently under investigation, are presented.
Published: 2004
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47. Morphology of Four Flow Fields on Titan: Implications for Modes of Origin

Author: Stofan, E. R., Farr, T., Kirk, R. L., Lopes, R. M., Lorenz, R., Lunine, J.I., Mitchell, K. L., Paillou, Philippe, Radebaugh, J., Wall, S. W., Wood, C. A., Cassini Radar Team, Proxemy Research Inc, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Wheeling Jesuit University
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: We describe four flow fields associated with channels that have been observed in Cassini Radar data of Titan.

48. Unforeseen plant phenotypic diversity in a dry and grazed world.

Author: Gross N, Maestre FT, Liancourt P, Berdugo M, Martin R, Gozalo B, Ochoa V, Delgado-Baquerizo M, Maire V, Saiz H, Soliveres S, Valencia E, Eldridge DJ, Guirado E, Jabot F, Asensio S, Gaitán JJ, García-Gómez M, Martínez P, Martínez-Valderrama J, Mendoza BJ, Moreno-Jiménez E, Pescador DS, Plaza C, Pijuan IS, Abedi M, Ahumada RJ, Amghar F, Arroyo AI, Bahalkeh K, Bailey L, Ben Salem F, Blaum N, Boldgiv B, Bowker MA, Branquinho C, van den Brink L, Bu C, Canessa R, Castillo-Monroy ADP, Castro H, Castro P, Chibani R, Conceição AA, Darrouzet-Nardi A, Davila YC, Deák B, Donoso DA, Durán J, Espinosa C, Fajardo A, Farzam M, Ferrante D, Franzese J, Fraser L, Gonzalez S, Gusman-Montalvan E, Hernández-Hernández RM, Hölzel N, Huber-Sannwald E, Jadan O, Jeltsch F, Jentsch A, Ju M, Kaseke KF, Kindermann L, le Roux P, Linstädter A, Louw MA, Mabaso M, Maggs-Kölling G, Makhalanyane TP, Issa OM, Manzaneda AJ, Marais E, Margerie P, Hughes FM, Messeder JVS, Mora JP, Moreno G, Munson SM, Nunes A, Oliva G, Oñatibia GR, Peter G, Pueyo Y, Quiroga RE, Ramírez-Iglesias E, Reed SC, Rey PJ, Reyes Gómez VM, Rodríguez A, Rolo V, Rubalcaba JG, Ruppert JC, Sala O, Salah A, Sebei PJ, Stavi I, Stephens C, Teixido AL, Thomas AD, Throop HL, Tielbörger K, Travers S, Undrakhbold S, Val J, Valkó O, Velbert F, Wamiti W, Wang L, Wang D, Wardle GM, Wolff P, Yahdjian L, Yari R, Zaady E, Zeberio JM, Zhang Y, Zhou X, and Le Bagousse-Pinguet Y
Subjects: Animals, Climate Change, Geographic Mapping, Biodiversity, Desert Climate, Herbivory physiology, Livestock physiology, Phenotype, Plants chemistry, Plants classification
Abstract: Earth harbours an extraordinary plant phenotypic diversity 1 that is at risk from ongoing global changes 2,3 . However, it remains unknown how increasing aridity and livestock grazing pressure-two major drivers of global change 4-6 -shape the trait covariation that underlies plant phenotypic diversity 1,7 . Here we assessed how covariation among 20 chemical and morphological traits responds to aridity and grazing pressure within global drylands. Our analysis involved 133,769 trait measurements spanning 1,347 observations of 301 perennial plant species surveyed across 326 plots from 6 continents. Crossing an aridity threshold of approximately 0.7 (close to the transition between semi-arid and arid zones) led to an unexpected 88% increase in trait diversity. This threshold appeared in the presence of grazers, and moved toward lower aridity levels with increasing grazing pressure. Moreover, 57% of observed trait diversity occurred only in the most arid and grazed drylands, highlighting the phenotypic uniqueness of these extreme environments. Our work indicates that drylands act as a global reservoir of plant phenotypic diversity and challenge the pervasive view that harsh environmental conditions reduce plant trait diversity 8-10 . They also highlight that many alternative strategies may enable plants to cope with increases in environmental stress induced by climate change and land-use intensification., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Published: 2024
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49. Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars.

Author: Farley KA, Stack KM, Shuster DL, Horgan BHN, Hurowitz JA, Tarnas JD, Simon JI, Sun VZ, Scheller EL, Moore KR, McLennan SM, Vasconcelos PM, Wiens RC, Treiman AH, Mayhew LE, Beyssac O, Kizovski TV, Tosca NJ, Williford KH, Crumpler LS, Beegle LW, Bell JF 3rd, Ehlmann BL, Liu Y, Maki JN, Schmidt ME, Allwood AC, Amundsen HEF, Bhartia R, Bosak T, Brown AJ, Clark BC, Cousin A, Forni O, Gabriel TSJ, Goreva Y, Gupta S, Hamran SE, Herd CDK, Hickman-Lewis K, Johnson JR, Kah LC, Kelemen PB, Kinch KB, Mandon L, Mangold N, Quantin-Nataf C, Rice MS, Russell PS, Sharma S, Siljeström S, Steele A, Sullivan R, Wadhwa M, Weiss BP, Williams AJ, Wogsland BV, Willis PA, Acosta-Maeda TA, Beck P, Benzerara K, Bernard S, Burton AS, Cardarelli EL, Chide B, Clavé E, Cloutis EA, Cohen BA, Czaja AD, Debaille V, Dehouck E, Fairén AG, Flannery DT, Fleron SZ, Fouchet T, Frydenvang J, Garczynski BJ, Gibbons EF, Hausrath EM, Hayes AG, Henneke J, Jørgensen JL, Kelly EM, Lasue J, Le Mouélic S, Madariaga JM, Maurice S, Merusi M, Meslin PY, Milkovich SM, Million CC, Moeller RC, Núñez JI, Ollila AM, Paar G, Paige DA, Pedersen DAK, Pilleri P, Pilorget C, Pinet PC, Rice JW Jr, Royer C, Sautter V, Schulte M, Sephton MA, Sharma SK, Sholes SF, Spanovich N, St Clair M, Tate CD, Uckert K, VanBommel SJ, Yanchilina AG, and Zorzano MP
Abstract: The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide-rich water under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.
Published: 2022
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50. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots.

Author: Reich PB, Luo Y, Bradford JB, Poorter H, Perry CH, and Oleksyn J
Subjects: Carbon metabolism, Databases, Factual, Hot Temperature, Biomass, Climate Change, Forests, Plant Leaves growth & development, Plant Roots growth & development, Plant Stems growth & development
Abstract: Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.
Published: 2014
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