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1. MIRS: an imaging spectrometer for the MMX mission

Author

Maria Antonietta Barucci, Jean-Michel Reess, Pernelle Bernardi, Alain Doressoundiram, Sonia Fornasier, Michel Le Du, Takahiro Iwata, Hiromu Nakagawa, Tomoki Nakamura, Yves André, Shohei Aoki, Takehiko Arai, Elisa Baldit, Pierre Beck, Jean-Tristan Buey, Elisabet Canalias, Matthieu Castelnau, Sebastien Charnoz, Marc Chaussidon, Fréderic Chapron, Valerie Ciarletti, Marco Delbo, Bruno Dubois, Stephane Gauffre, Thomas Gautier, Hidenori Genda, Rafik Hassen-Khodja, Gilles Hervet, Ryuki Hyodo, Christian Imbert, Takeshi Imamura, Laurent Jorda, Shingo Kameda, Driss Kouach, Toru Kouyama, Takeshi Kuroda, Hiroyuki Kurokawa, Laurent Lapaw, Jeremie Lasue, Laetitia Le Deit, Aurélien Ledot, Cedric Leyrat, Bertrand Le Ruyet, Moe Matsuoka, Frederic Merlin, Hideaki Miyamoto, Frederic Moynier, Napoleon Nguyen Tuong, Kazunori Ogohara, Takahito Osawa, Jérôme Parisot, Laurie Pistre, Benjamin Quertier, Sean N. Raymond, Francis Rocard, Takeshi Sakanoi, Takao M. Sato, Eric Sawyer, Fériel Tache, Sylvain Trémolières, Fuminori Tsuchiya, Pierre Vernazza, and Didier Zeganadin

Subjects
MIRS, MMX, Imaging spectrometer, Phobos, Deimos, Mars, Geography. Anthropology. Recreation, Geodesy, QB275-343, Geology, QE1-996.5
Abstract

Abstract The MMX infrared spectrometer (MIRS) is an imaging spectrometer onboard MMX JAXA mission. MMX (Martian Moon eXploration) is scheduled to be launched in 2024 with sample return to Earth in 2029. MIRS is built at LESIA-Paris Observatory in collaboration with four other French laboratories, collaboration and financial support of CNES and close collaboration with JAXA and MELCO. The instrument is designed to fully accomplish MMX’s scientific and measurement objectives. MIRS will remotely provide near-infrared spectral maps of Phobos and Deimos containing compositional diagnostic spectral features that will be used to analyze the surface composition and to support the sampling site selection. MIRS will also study Mars atmosphere, in particular spatial and temporal changes such as clouds, dust and water vapor. Graphical Abstract

Published
2021
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2. Clustering Supported Classification of ChemCam Data From Gale Crater, Mars

Author

Kristin Rammelkamp, Olivier Gasnault, Olivier Forni, Candice C. Bedford, Erwin Dehouck, Agnès Cousin, Jeremie Lasue, Gaël David, Travis S. J. Gabriel, Sylvestre Maurice, and Roger C. Wiens

Subjects
ChemCam, Mars, LIBS, clustering, classification, Astronomy, QB1-991, Geology, QE1-996.5
Abstract

Abstract The Chemistry and Camera (ChemCam) instrument on board the Mars Science Laboratory (MSL) rover Curiosity has collected a very large and unique data set of in‐situ spectra and images of Mars since landing in August 2012. More than 800,000 single shot laser‐induced breakdown spectroscopy (LIBS) spectra measured on more than 2,500 individual targets were returned so far by ChemCam. Such a data set is ideally suited for the application of statistical methods for the recognition of patterns that are difficult to observe by humans. In this work, we develop an approach relying on the feature extraction method Non‐Negative Matrix Factorization (NMF) and the repetition of k‐means clustering to classify ChemCam spectra. A strong consistency of the clustering results among the repetitions were found, which allowed us to identify six clusters representing the dominant compositions measured by ChemCam in Gale crater so far. By tracking clusters across the rover traverse from landing to sol 2756, we are able to provide a chemostratigraphic overview of the Gale crater from the ChemCam perspective. Transitions between major geologic groups (such as the Bradbury and the Mt. Sharp groups) are identifiable demonstrating that they are compositionally distinct, consistent with previous work. Compositional differences between their members also appear in the results. Furthermore, a first approach in which a random forest classifier was trained and validated with the obtained cluster assignments, reveals promising results for predicting cluster memberships of new ChemCam LIBS data acquired after sol 2756.

Published
2021
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3. 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 M Ollila, Susanne Schroder, Olivier Beyssac, Erin Gibbons, David S Vogt, Elise Clave, Jose-Antonio Manrique, Carey Legett IV, Paolo Pilleri, Raymond T Newell, Joseph Sarao, Sylvestre Maurice, Gorka Arana, Karim Benzerara, Pernelle Bernardi, Sylvian Bernard, Bruno Bousquet, Adrian J Brown, Cesar-Alvarez Llamas, Baptiste Chide, Edward Cloutis, Jade Comellas, Stephanie Connell, Erwin Dehouck, Dorothea M Delapp, Ari Essunfeld, Cecile Fabre, Thierry C Fouchet, Cristina Garcia-Florentino, Laura Garcia-Gomez, Patrick Gasda, Olivier Gasnault, Elisabeth 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, and Bethany Ehlmann

Subjects
Geosciences (General)
Abstract

The SuperCam instrument on the PerseveranceMars 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 andspectra are normalized to minimize signal fluctuations and effectsof target distance.In some cases, the spectra are also standardized or binned prior to quantification. To determine quantitative elemental compositionsof 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 oreand sodalite), andreplicates of the sintered SuperCam calibration targets (SCCTs) onboardthe 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 fourfolds 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 3m. 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
2021
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4. The SuperCam Instrument Suite on the NASA Mars 2020 Rover: Body Unit and Combined System Tests

Author

Roger C. Wiens, Sylvestre Maurice, Scott H. Robinson, Anthony E. Nelson, Philippe Cais, Pernelle Bernardi, Raymond T. Newell, Sam Clegg, Shiv K. Sharma, Steven Storms, Jonathan Deming, Darrel Beckman, Ann M. Ollila, Olivier Gasnault, Ryan B. Anderson, Yves André, S. Michael Angel, Gorka Arana, Elizabeth Auden, Pierre Beck, Joseph Becker, Karim Benzerara, Sylvain Bernard, Olivier Beyssac, Louis Borges, Bruno Bousquet, Kerry Boyd, Michael Caffrey, Jeffrey Carlson, Kepa Castro, Jorden Celis, Baptiste Chide, Kevin Clark, Edward Cloutis, Elizabeth C. Cordoba, Agnes Cousin, Magdalena Dale, Lauren Deflores, Dorothea Delapp, Muriel Deleuze, Matthew Dirmyer, Christophe Donny, Gilles Dromart, M. George Duran, Miles Egan, Joan Ervin, Cecile Fabre, Amaury Fau, Woodward Fischer, Olivier Forni, Thierry Fouchet, Reuben Fresquez, Jens Frydenvang, Denine Gasway, Ivair Gontijo, John Grotzinger, Xavier Jacob, Sophie Jacquinod, Jeffrey R. Johnson, Roberta A. Klisiewicz, James Lake, Nina Lanza, Javier Laserna, Jeremie Lasue, Stéphane Le Mouélic, Carey Legett, Richard Leveille, Eric Lewin, Guillermo Lopez-Reyes, Ralph Lorenz, Eric Lorigny, Steven P. Love, Briana Lucero, Juan Manuel Madariaga, Morten Madsen, Soren Madsen, Nicolas Mangold, Jose Antonio Manrique, J. P. Martinez, Jesus Martinez-Frias, Kevin P. McCabe, Timothy H. McConnochie, Justin M. McGlown, Scott M. McLennan, Noureddine Melikechi, Pierre-Yves Meslin, John M. Michel, David Mimoun, Anupam Misra, Gilles Montagnac, Franck Montmessin, Valerie Mousset, Naomi Murdoch, Horton Newsom, Logan A. Ott, Zachary R. Ousnamer, Laurent Pares, Yann Parot, Rafal Pawluczyk, C. Glen Peterson, Paolo Pilleri, Patrick Pinet, Gabriel Pont, Francois Poulet, Cheryl Provost, Benjamin Quertier, Heather Quinn, William Rapin, Jean-Michel Reess, Amy H. Regan, Adriana L. Reyes-Newell, Philip J. Romano, Clement Royer, Fernando Rull, Benigno Sandoval, Joseph H. Sarrao, Violaine Sautter, Marcel J. Schoppers, Susanne Schröder, Daniel Seitz, Terra Shepherd, Pablo Sobron, Bruno Dubois, Vishnu Sridhar, Michael J. Toplis, Imanol Torre-Fdez, Ian A. Trettel, Mark Underwood, Andres Valdez, Jacob Valdez, Dawn Venhaus, and Peter Willis

Published
2020
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5. Spectral behavior of regolith analogues weathered by heating under reducing conditions

Author

Jeremie Lasue, Patrick Pinet, Pierre Beck, Mike Toplis, Pascal Munsch, and Marine Oustric

Abstract

Introduction: Airless bodies of the Solar System present surface evolution due to space weathering. Their regolith is exposed to thermal cycling, cosmic and solar-irradiation, solar wind sputtering and micrometeorites bombardment and associated vaporization. With time, these materials accumulate optically active opaque particles such as nanophase metallic iron on the surface or rims of dust grains or larger iron particles. The density increase in iron particles modifies the spectral properties of the material with a lowering of the albedo, and of the amplitude of absorption bands, generally associated with a global reddening of the spectral slope [1, 2]. Previous studies have shown that nanophase iron particles that induce spectral properties typical of space-weathering will accumulate at the surface of olivine and pyroxene minerals at temperature conditions corresponding to micrometeorite impacts [3]. The skin depth of weathered material depends on the weathering process and minerals. Context for Phobos studies: The moons of Mars, Phobos and Deimos, are some of the most enigmatic small bodies of the Solar System. Indeed, it is still debated in the community whether they originate from a large impact on Mars [4, 5], or if they are captured primitive asteroids [6]. The overall spectra of Phobos and Deimos have a strong red slope with no obvious diagnostic spectral features readily detected in the visible or near-infrared, similar to very primitive small bodies of the solar system. However, significant variations in the spectral slope indicate inhomogeneities of the material on the surface of Phobos, suggesting mixture of asteroidal and basaltic materials [7]. The Mars Moons Explorer (MMX) mission will bring back samples of Phobos to Earth in order to decipher the origin of the Martian Moons system [8]. The MMX InfraRed Spectrometer (MIRS) instrument on-board the mission is an infrared imaging spectrometer (0.9 to 3.6 μm) that will study the spectral properties of the surface of Phobos and Mars. Laboratory analogue samples: In this context, laboratory analogues were ‘weathered’ artificially by submitting basalt (such as the Pic d’Ysson basalt already used for laboratory studies on the lunar regolith optical and spectrophotometric behavior [9]) and meteorite samples to near fusion temperature (1000°C) in an controlled-atmosphere furnace under reducing conditions (partial pressure of CO/CO2 of 96% corresponding to an oxygen fugacity of about 10-17) for exposure times of a 2, 4 and 8 hours (Figure 1; [10]). Fig. 1: The controlled-atmosphere furnace at IRAP used for heating under reducing conditions [10]. Analysis of the weathered samples : A first comparison between unaltered Pic d’Ysson basalt grains and grains subjected to 4 hours heating at 1100°C under reducing conditions (fugacity of 10-17) is presented in Figure 2. Backscattered SEM images of basaltic grains before and after exposure are compared. The unaltered grain presents a typical crystalline structure with olivine, feldspars and ilmenite (bright minerals). Its bulk composition is given in Table 1. Tab. 1: Elemental bulk composition of the Pic d’Ysson basalt unweathered (values given in wt.%). When considering the altered basalt grain, the onset of alteration due to heating is clearly seen over a depth of about 30 microns (top left and left side of the images), with partial melting of the minerals and the appearance of nanophase metallic iron phases (presence of small white grains on the surface and inside the minerals). Spectral analysis : The near infrared reflectance spectra of the ‘unweathered’ (pristine) and ‘weathered’ (heat-treated) samples (1050°C for 4 hours) are then acquired with the SHADOWS instrument at IPAG [11]. The resulting spectra are illustrated in Figure 3 (unweathered in red, weathered in blue). The weathered samples (powdered or sintered) demonstrate a significant change of slope with a strong visible reddening of the spectrum. At the same time the crystal infrared absorption bands depths are generally reduced. Fig. 2 : SEM analysis showing the onset of heat diffusion and iron metal formation left: crystalline basalt grain unaltered showing the presence of olivine and feldspar crystals with ilmenite (bright minerals). right: apparition of nanophase Fe over a 30 μm depth after 4 hrs heating at 1100°C under reducing conditions. Fig. 3 : NIR analysis of samples heated at 1050°C for 4 hours with SHADOWS [11] showing the reddening of the spectral slope between unaltered sample (red) and weathered samples (light blue: sintered; dark blue: powdered). Conclusions and perspectives : Laboratory simulations show that heat-treated samples under reducing conditions can recreate the conditions under which regolith may be weathered in space with surface alteration of grains and appearance of nanophase iron. The analysis of the grains’ spectral properties indicates significant reddening and decrease of the absorption band depths as seen on space weathered surfaces. For the moment, the slopes reached remain lower than the ones seen on the surface of Phobos and Deimos. Now that the weathering concept has been demonstrated, further experiments will be performed using Mars analogues and meteorite samples to better constrain the possible materials on the surface of Phobos. Grain size distribution effects will also be explored. Acknowledgment: this study was funded by CNES. References: [1] Hapke, B. (2001) JGR, 106(E5), 10039-10073. [2] Pieters, C.M., & Noble, S.K. (2016) JGR, 121(10), 1865-1884. [3] Weber, I., et al. (2020) EPSL, 530, 115884. [4] Canup, R., & Salmon, J. (2018) Science advances, 4(4), eaar6887. [5] Bagheri, A., et al. (2021) Nature Astronomy, 1-5. [6] Hansen, B. M. (2018) MNRAS, 475(2), 2452-2466. [7] Glotch, T. D., et al. (2018) JGR: Planets, 123(10), 2467-2484. [8] Kuramoto, K., et al. (2021) Earth, Planets and Space. Submitted. [9] Souchon, A.L., et al. (2011) Icarus, 215(1), 313-331. [10] Toplis, M.J., & Corgne, A. (2002) Contributions to Mineralogy and Petrology, 144(1), 22-37. [11] Potin, S., et al. (2018) Applied optics, 57(28), 8279-8296.

Published
2022

6. Primitiveness of cometary dust collected by MIDAS on-boardRosetta

Author

Minjae Kim, Thurid Mannel, Jeremie Lasue, Andrea Longobardo, Mark Bentely, and Richard Moissl

Abstract

Comets are thought to have preserved dust particles from the very beginning of Solar System formation, providing a unique insight into intricate processes like dust growth mechanisms. The Rosetta mission offered the best opportunity to investigate nearly pristine cometary dust particles of comet 67P/Churyumov–Gerasimenko. In particular, among the three in-situ dust instruments, the MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope collected cometary dust particles with sizes from hundreds of nanometres to tens of micrometres on dedicated targets and recorded their 3D topographic information and related parameters (Bentley et al. 2016a). However, the straightforward dust collection strategy, i.e., simply hitting the collection targets, leads to an unknown degree of collection alteration (Mannel et al. 2016; Bentley et al. 2016b). We aim to understand dust alteration during collection and determine which structural properties of the MIDAS dust particle remained pristine. An exhaustive dust particle catalogue for MIDAS is created, containing 3494 dust particles with (meta)data. Among these particles, we carefully select 1082 particles that are eligible for a more extensive structural investigation. First, we generate sophisticated dust maps showing the distribution of the selected dust particles on the collection targets and investigate dust clustering, i.e., determination of which of the particles stem from a single parent particle that fragmented upon the collection impact. Additionally, in the collaboration with Longobardo et al. in preparation, we use an algorithm to determine from which cometary source regions which MIDAS particles were stemming (Longobardo et al. 2020). Next, we develop MIDAS particle shape descriptors such as aspect ratio (i.e., height of the particle divided by the square root of area; Lasue et al. 2019), elongation, circularity, convexity, and particle surface/volume distribution. Furthermore, we compare the structure of the MIDAS dust particles and the clusters to those found in the laboratory experiments (Ellerborek et al. 2017) and by COSIMA/Rosetta (Langevin et al. 2016). Finally, we combine our findings to calculate a pristinity score for MIDAS particles and determine the most pristine particles and their properties. Fig 1. 3D dust coverage map of target 13 We find there is only a weak trend between shape descriptors and cometary source regions, cluster morphology, and particle characteristics such as size and particle morphology. For example, particles ejected from smooth or rough terrain are similar in their investigated shape properties, which implies dust particle activity such as dust ejection, partial dry out, and recycled dust material are not responsible for the structure of particles at the micrometre scale. Furthermore, the aspect ratio distributions suggest that the subunits of different cluster types are similar in their shape and composition. Thus, the different cluster morphologies detected by MIDAS are not created by a change in subunit properties, but rather by different impact velocities, a result in good agreement with the finding of laboratory experiments (Ellerbroek et al. 2017) and simulations (Lasue et al. 2019). Next, the types of clusters found in MIDAS show good agreement (Ellerbroek et al. 2017), however, there are some differences to those found by COSIMA (Lasue et al. 2019). Furthermore, our pristinity score shows that almost half of MIDAS particles suffered severe alteration by impact, which indicates dust alteration was inevitable with the given dust collection strategy. Consequently, only ~ 20 particles were rated 'moderately pristine' particles, i.e., they are not substantially flattened by impact, not fragmented, and/or not part of a fragmentation cluster. The microphysical properties of pristine cometary materials are established in this study and can be translated into properties of laboratory analogue materials for future study to understand comets and early Solar System processes.

Published
2022

7. Primitiveness of cometary dust collected by MIDAS on-board Rosetta

Author

Minjae Kim, Thurid Mannel, Jeremie Lasue, Andrea Longobardo, Mark Bentley, and Richard Moissl

Abstract

Comets are thought to have preserved dust particles from the beginning of Solar System formation, providing a unique insight into dust growth mechanisms. The Rosetta mission offered the best opportunity to investigate nearly pristine cometary dust particles of comet 67P/Churyumov–Gerasimenko. Among the three in-situ dust instruments, the MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope collected cometary dust particles with sizes from hundreds of nanometres to tens of micrometres on dedicated targets and recorded their 3D topographic information (Bentley et al. 2016a). However, the straightforward dust collection strategy, i.e., simply hitting the collection targets, leads to an unknown degree of collection alteration (Bentley et al. 2016b) We aim to understand and determine which structural properties of the MIDAS dust particle remained pristine during collection. First, we generate sophisticated dust maps showing the distribution of the dust particles on the collection targets and investigate dust clustering, i.e., determination of which particles stem from a single parent particle that fragmented upon the collection impact. Additionally, in the collaboration with Longobardo et al. 2020a, we use an algorithm to determine from which cometary source regions which MIDAS particles were stemming (Longobardo et al. 2020b). Next, we develop MIDAS particle shape descriptors such as aspect ratio (i.e., height of the particle divided by the square root of area), elongation, circularity, convexity, and particle surface/volume distribution. Furthermore, we compare structures of the MIDAS dust particles and clusters to those found in the laboratory experiments (Ellerborek et al. 2017) and by COSIMA/Rosetta (Langevin et al. 2016). Finally, we combine our findings to calculate a pristinity score for MIDAS particles and determine the most pristine particles and their properties. Fig 1. 3D dust coverage map of target 10We find that there is only a weak trend between shape descriptors and cometary source regions, cluster morphology, and particle characteristics. For example, particles ejected from smooth or rough terrain are similar in their shape properties, which implies that dust particle activity such as dust ejection, partial dry out, and backfall are not responsible for the structure of particles at micrometre scales. Furthermore, the aspect ratio distributions suggest that the subunits of different cluster types are similar in their shape and composition. Thus, the different cluster morphologies detected by MIDAS are not created by a change in subunit properties, but rather by different impact velocities (Lasue et al. 2019). Next, the types of clusters found in MIDAS show good agreement (Ellerbroek et al. 2017), however, there are some differences to those found by COSIMA (Lasue et al. 2019). Furthermore, we found that almost half of the MIDAS particles suffered severe alteration by impact, which indicates dust alteration was inevitable with the given dust collection strategy. Consequently, only ~ 20 particles were rated 'moderately pristine' particles, i.e., not substantially flattened by impact, not fragmented, and/or not part of a fragmentation cluster. The microphysical properties of pristine cometary materials are established in this study and can be translated into properties of laboratory analogue materials for future study.

Published
2022

8. 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

9. Collection alteration and pristine structural properties of dust particles collected by MIDAS/Rosetta at comet 67P/Churyumov-Gerasimenko

Author

Minjae Kim, Thurid Mannel, Jeremie Lasue, Mark Bentely, and Richard Moissl

Abstract

Comets are believed to have preserved pristine material from the early stages of the Solar System formation, thus providing unique information on intricate processes like dust growth mechanisms. The Rosetta mission gave us the best opportunity to investigate nearly pristine cometary dust particles of comet 67P/Churyumov–Gerasimenko. Among the three in-situ dust instruments, the MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope collected cometary dust particles with sizes from hundreds of nanometres to tens of micrometres and recorded their 3D topography, size, shape, morphology, and related parameters [1]. MIDAS collected dust emitted from comet 67P on dedicated targets. Particles fell through the entry funnel and collided with the collection targets [2] causing an unknown degree of particle alteration. To understand which structural properties of the dust remained pristine and can be used to understand comets and early Solar System processes it is important to understand the collection alteration. Dedicated laboratory experiments were carried out by previous studies [3, 4]. They found that the degree of alteration upon collection is strongly determined by the particle size, strength, and the collection velocity. They indicate that particles in the MIDAS size range deposited with moderate velocities about less than a few metres per second can stick on a target without major alteration. We aim to determine the structurally least altered MIDAS particles and investigate their properties. As database we use an improved version of the MIDAS particle catalogue [5]. Selecting all particles suitable for our analysis (e.g., cometary origin, sufficiently high image quality) grants us topographic data of over 600 nano- to micrometre-sized dust particles of comet 67P. We create dust coverage maps showing the distribution of the selected dust particles on the collection targets. As first, simple classification we divide the particles into those detected in clusters, suggested to be fragments originating in a shattering event of one large parent particle, and those remote from others that are potentially individually collected particles. Finally, we use a shape descriptor to categorise the particles according to their characteristics, e.g., shape and size, and compare to previous results from COSIMA [6] and simulation/laboratory studies [3, 7]. [1] Bentley, M.S., Schmied, R., Mannel, T., et al. 2016, Nature, 537 [2] Bentley, M. S., Arends, H., Butler, B., et al. 2016, Acta Astronautica, 125, 11 [3] Ellerbroek, L. E., Gundlach, B., Landeck, A., et al. 2017, MNRAS, 469, S204 [4] Ellerbroek, L. E., Gundlach, B., Landeck, A., et al. 2019, MNRAS, 486, S3755 [5] Boakes, P., and the MIDAS team, 2018. ‘MIDAS Particle Catalogue’. ESA Planetary Science Archive Dataset: RO-C-MIDAS-5-PRL-TO-EXT3-V2.0. Product ID: RO-C-MIDAS-5-PRL-TO-EXT3-V2.0 [6] Langevin, Y., Hilchenbach, M., Ligier, N., et al. 2016, Icarus, 271, 76 [7] Lasue, J., Maroger, I., Botet, R., et al. 2019, A&A, 630

Published
2021

10. First atmospheric results produced by the SuperCam instrument on Mars2020

Author

Franck Montmessin, Timothy McConnochie, Thierry Fouchet, Olivier Forni, Paolo Pilleri, Clément Royer, Elise Knutsen, Tanguy Bertrand, Olivier Gasnault, Jeremie Lasue, Carey Legett, Mark Lemmon, Raymond Newell, Dawn Venhaus, Sylvestre Maurice, Roger Wiens, and Fouchet, Thierry

Subjects
[SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

The SuperCam instrument [1,2] onboard Mars2020 disposes of a variety of active and passive techniques, including passive spectroscopy in the 0.40-0.85 (VIS) and 1.3 to 2.6 microns (IR, [3,4]) wavelength ranges. Since the landing on Mars of Perseverance in February 2021, Supercam has acquired numerous observations of its near and distant environment, exploring the geological and mineralogical context of Jezero crater. In addition, several measurements were devoted to probing the atmosphere surrounding the Perseverance rover. The technique of using sky spectra in passive mode, known as "passive sky", has already been demonstrated with ChemCam on the Mars Science Laboratory (MSL) rover [4]. SuperCam provides a superset of the ChemCam capabilities used in [4], and in particular adds a near-infrared component that includes absorption and scattering characteristics of key gases and aerosols/clouds. "Passive sky" measurements have typically been performed every other week to allow a consistent monitoring of the seasonal evolution of the main quantities (CO2, O2, H2O, CO, aerosols/clouds). Particular attention was given to joint measurements of O2 and CO, as they appear as key components of the Martian chemical cycle and have never been measured together at the same time on the surface of Mars. As the 2 m wavelength region is used for the first time at the surface of Mars, it enables the detection of CO (around 2.35 m). CO possesses a small absorption that has made it difficult to identify in SuperCam spectra so far. An overview of SuperCam's progress to date in its attempt to characterize the Martian atmosphere at Jezero will be presented. References : [1] Wiens, R.C., et al. , 2021. Space Sci Rev 217, 4, [2] Maurice, S., et al., 2021. Space Sci Rev 217, 47, [3] Royer, C., et al.., 2020. Review of Scientific Instruments 91, 063105, [4] Fouchet, T., et al., 2021, Icarus, submitted. [5] McConnochie T. H et al., 2018. Icarus 307, 294

Published
2021

11. Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team

Author

Kathryn M. Stack, Nathan R. Williams, Fred Calef, Vivian Z. Sun, Kenneth H. Williford, Kenneth A. Farley, Sigurd Eide, David Flannery, Cory Hughes, Samantha R. Jacob, Linda C. Kah, Forrest Meyen, Antonio Molina, Cathy Quantin Nataf, Melissa Rice, Patrick Russell, Eva Scheller, Christina H. Seeger, William J. Abbey, Jacob B. Adler, Hans Amundsen, Ryan B. Anderson, Stanley M. Angel, Gorka Arana, James Atkins, Megan Barrington, Tor Berger, Rose Borden, Beau Boring, Adrian Brown, Brandi L. Carrier, Pamela Conrad, Henning Dypvik, Sarah A. Fagents, Zachary E. Gallegos, Brad Garczynski, Keenan Golder, Felipe Gomez, Yulia Goreva, Sanjeev Gupta, Svein-Erik Hamran, Taryn Hicks, Eric D. Hinterman, Briony N. Horgan, Joel Hurowitz, Jeffrey R. Johnson, Jeremie Lasue, Rachel E. Kronyak, Yang Liu, Juan Manuel Madariaga, Nicolas Mangold, John McClean, Noah Miklusicak, Daniel Nunes, Corrine Rojas, Kirby Runyon, Nicole Schmitz, Noel Scudder, Emily Shaver, Jason SooHoo, Russell Spaulding, Evan Stanish, Leslie K. Tamppari, Michael M. Tice, Nathalie Turenne, Peter A. Willis, R. Aileen Yingst, Unidad de Excelencia Científica Centro de Astrobiología María de Maeztu del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Molina, A. [0000-0002-5038-2022], Hughes, C. [0000-0002-7061-1443], Jacob, S. [0000-0001-9950-1486], Arana, Gorka [0000-0001-7854-855X], Sun, V. Z. [0000-0003-1480-7369], Stack, K. [0000-0003-3444-6695], Williford, K. [0000-0003-0633-408X], Flannery, D. [0000-0001-8982-496X], Gupta, S. [0000-0001-6415-1332], Williams, N. [0000-0003-0602-484X], European Research Council (ERC), and National Aeronautics and Space Administration (NASA)

Subjects
010504 meteorology & atmospheric sciences, Mars, Fluvial, Perseverance, 01 natural sciences, Article, Impact crater, 0103 physical sciences, Rover, Impact structure, Digital elevation model, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Bedrock, Astronomy and Astrophysics, Jezero, Mars Exploration Program, 15. Life on land, Geologic map, Planetary science, Space and Planetary Science, Geologic mapping, Geology
Abstract

Stack, K. et al., The Mars 2020 Perseverance rover landing site is located within Jezero crater, a ∼50km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study’s map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance’s exploration of Jezero crater., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Published
2020

12. Contributors

Author

Muhammad Sher Afgan, K.K. Ayyalasomayajula, Halil Berberoglu, Chet R. Bhatt, Gonca Bilge, Alexander A. Bol'shakov, Ismail Hakkı Boyaci, B. Busser, Beatrice Campanella, Daniel Diaz, P.K. Diwakar, Kemal Efe Eseller, C. Fabre, Ghaneshwar Gautam, J.J. Gonzalez, Jennifer L. Gottfried, Christian L. Goueguel, Manoj Kumar Gundawar, David W. Hahn, S.S. Harilal, Richard R. Hark, Russell S. Harmon, Christopher M. Helstern, Zongyu Hou, Jinesh C. Jain, Rohit Kumar, Jeremie Lasue, Stefano Legnaioli, X.L. Mao, Sylvestre Maurice, Gulab Singh Maurya, Dustin L. McIntyre, G. Miloshevsky, S. Moncayo, V. Motto-Ros, Reinhard Noll, Stefano Pagnotta, Vincenzo Palleschi, Ulrich Panne, Christian G. Parigger, Jayanta Kumar Pati, Francesco Poggialini, Abhishek Kumar Rai, Awadhesh Kumar Rai, Pradeep Kumar Rai, V.N. Rai, Richard E. Russo, Herve K. Sanghapi, Giorgio S. Senesi, Banu Sezer, Sahar Sheta, Jagdish P. Singh, Rajesh Kumar Singh, David M. Surmick, Surya N. Thakur, Pravin Kumar Tiwari, Markandey M. Tripathi, Xiong Wan, Zhe Wang, Roger C. Wiens, Shunchun Yao, J. Yoo, Fang Y. Yueh, and Lei Zhang

Published
2020

13. 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

14. Structure and Formation of Comets: Updates from Post-Rosetta Solid Fraction Analyses

Author

Anny Chantal Levasseur-Regourd, Mark Stephen Bentley, Wlodek Kofman, Yann Brouet, Valérie Ciarletti, Edith Hadamcik, Alain Herique, Jeremie Lasue, Thurid Mannel, Roland Schmied, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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)-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), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Physikalisches Institut [Bern], Universität Bern [Bern], Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), 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), Universität Bern [Bern] (UNIBE), 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
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; he combination of investigations of 67P/C-G by Rosetta, theoretical and experimental studies, and remote observations allowed unprecedented insight into the structure and formation of comets. Rosetta mission has provided ground-truth for the low-density and high porosity of the nucleus, without heterogeneities larger than a few meters in its small lobe [1,2]. Further studies related to CONSERT experiment now suggest that the porosity increases inside the nucleus [3,4]. Rosetta has also provided ground-truth for the aggregated structure of dust particles within a wide range of sizes in the inner coma [e.g. 5-7]. Such discoveries confirm previous interpretations of remote observations of solar light scattered by dust in cometary comae. Differences in structure between the two parts of the nucleus, strongly suspected from previous high-resolution images of the surface [8] and possibly suggested from some remote observations in fragmenting sub-nuclei [9], might be pointed out from data obtained shortly before Rosetta controlled descent in September 2016.Further analyses by MIDAS of dust particles morphology at submicron-sizes [7,10], as well as compilations of remote observations of solar light scattered by 67P/C-G [11], are presently taking place. We will discuss how such results could lead to a better understanding of dust growth processes during the formation, specifically of 67P/C-G, and more generally, thanks to the link now provided between structural properties of dust and remote polarimetric observations, of comet’s nuclei in the early Solar System.References. 1 Kofman et al. Science 2015. 2 Pätzold et al. Nature 2016. 3 Ciarletti et al. A&A 2015. 4 Brouet et al. MNRAS

Published
2016

15. Cosmochemical implications of CONSERT permittivity characterization of 67P/C-G

Author

Anny Chantal Levasseur-Regourd, Alain Hérique, Wlodek Kofman, Pierre Beck, Lydie Bonal, Ilaria Buttarazzi, Essam Heggy, Jeremie Lasue, Eric Quirico, Sonia Zine, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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)-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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), University of Southern California (USC), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National d'Etudes Spatiales (CNES), PLANETO - LATMOS, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), 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), 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
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract

International audience; Unique information about the internal structure of the nucleus of comet 67P/C-G was provided by the CONSERT bistatic radar on-board Rosetta and Philae [1]. Analysis of the propagation of its signal throughout the small lobe indicated that the real part of the permittivity at 90 MHz is of (1.27±0.05). The first interpretation of this value using dielectric properties of mixtures of dust and ices (H2O, CO2), led to the conclusion that the comet porosity ranges between 75–85%. In addition, the dust/ice ratio was found to range between 0.4-2.6 and the permittivity of dust (including 30% of porosity) was determined to be lower than 2.9.The dust permittivity estimate is now reduced by taking into account the updated values of nucleus density and of dust/ice ratio, in order of providing further insights into the nature of the constituents of comet 67P/C-G [2]. We adopt a systematic approach: i) determination of the dust permittivity as a function of the ice (I) to dust (D) and vacuum (V) volume fraction; ii) comparison with the permittivity of meteoritic, mineral and organic materials from literature and laboratory measurements; iii) test of several composition models of the nucleus, corresponding to cosmochemical end members of 67P/C-G. For each of these models the location in the ternary I/D/V diagram is calculated based on available dielectric measurements, and confronted to the locus of 67P/C-G. The number of compliant models is small and the cosmochemical implications of each are discussed [2]. An important fraction of carbonaceous material is required in the dust in order to match CONSERT permittivity observations, establishing that comets represent a massive carbon reservoir.Support from Centre National d'Études Spatiales (CNES, France) for this work, based on observations with CONSERT on board Rosetta, is acknowledged. The CONSERT instrument was designed, built and operated by IPAG, LATMOS and MPS and was financially supported by CNES, CNRS, UJF/UGA, DLR and MPS. Rosetta is an ESA mission with contributions from its member states and NASA.[1] Kofman et al., Science, 349, 6247, aaa0639, 2015. [2] Herique et al., MNRAS, submitted, 2016.

Published
2016

16. Isotope ratios of H, C, and O in CO2 and H2O of the martian atmosphere

Author

Chris R, Webster, Paul R, Mahaffy, Gregory J, Flesch, Paul B, Niles, John H, Jones, Laurie A, Leshin, Sushil K, Atreya, Jennifer C, Stern, Lance E, Christensen, Tobias, Owen, Heather, Franz, Robert O, Pepin, Andrew, Steele, Cherie, Achilles, Christophe, Agard, José Alexandre, Alves Verdasca, Robert, Anderson, Ryan, Anderson, Doug, Archer, Carlos, Armiens-Aparicio, Ray, Arvidson, Evgeny, Atlaskin, Andrew, Aubrey, Burt, Baker, Michael, Baker, Tonci, Balic-Zunic, David, Baratoux, Julien, Baroukh, Bruce, Barraclough, Keri, Bean, Luther, Beegle, Alberto, Behar, James, Bell, Steve, Bender, Mehdi, Benna, Jennifer, Bentz, Gilles, Berger, Jeff, Berger, Daniel, Berman, David, Bish, David F, Blake, Juan J, Blanco Avalos, Diana, Blaney, Jen, Blank, Hannah, Blau, Lora, Bleacher, Eckart, Boehm, Oliver, Botta, Stephan, Böttcher, Thomas, Boucher, Hannah, Bower, Nick, Boyd, Bill, Boynton, Elly, Breves, John, Bridges, Nathan, Bridges, William, Brinckerhoff, David, Brinza, Thomas, Bristow, Claude, Brunet, Anna, Brunner, Will, Brunner, Arnaud, Buch, Mark, Bullock, Sönke, Burmeister, Michel, Cabane, Fred, Calef, James, Cameron, John, Campbell, Bruce, Cantor, Michael, Caplinger, Javier, Caride Rodríguez, Marco, Carmosino, Isaías, Carrasco Blázquez, Antoine, Charpentier, Steve, Chipera, David, Choi, Benton, Clark, Sam, Clegg, Timothy, Cleghorn, Ed, Cloutis, George, Cody, Patrice, Coll, Pamela, Conrad, David, Coscia, Agnès, Cousin, David, Cremers, Joy, Crisp, Alain, Cros, Frank, Cucinotta, Claude, d'Uston, Scott, Davis, Mackenzie, Day, Manuel, de la Torre Juarez, Lauren, DeFlores, Dorothea, DeLapp, Julia, DeMarines, David, DesMarais, William, Dietrich, Robert, Dingler, Christophe, Donny, Bob, Downs, Darrell, Drake, Gilles, Dromart, Audrey, Dupont, Brian, Duston, Jason, Dworkin, M Darby, Dyar, Lauren, Edgar, Kenneth, Edgett, Christopher, Edwards, Laurence, Edwards, Bethany, Ehlmann, Bent, Ehresmann, Jen, Eigenbrode, Beverley, Elliott, Harvey, Elliott, Ryan, Ewing, Cécile, Fabre, Alberto, Fairén, Ken, Farley, Jack, Farmer, Caleb, Fassett, Laurent, Favot, Donald, Fay, Fedor, Fedosov, Jason, Feldman, Sabrina, Feldman, Marty, Fisk, Mike, Fitzgibbon, Melissa, Floyd, Lorenzo, Flückiger, Olivier, Forni, Abby, Fraeman, Raymond, Francis, Pascaline, François, Caroline, Freissinet, Katherine Louise, French, Jens, Frydenvang, Alain, Gaboriaud, Marc, Gailhanou, James, Garvin, Olivier, Gasnault, Claude, Geffroy, Ralf, Gellert, Maria, Genzer, Daniel, Glavin, Austin, Godber, Fred, Goesmann, Walter, Goetz, Dmitry, Golovin, Felipe, Gómez Gómez, Javier, Gómez-Elvira, Brigitte, Gondet, Suzanne, Gordon, Stephen, Gorevan, John, Grant, Jennifer, Griffes, David, Grinspoon, John, Grotzinger, Philippe, Guillemot, Jingnan, Guo, Sanjeev, Gupta, Scott, Guzewich, Robert, Haberle, Douglas, Halleaux, Bernard, Hallet, Vicky, Hamilton, Craig, Hardgrove, David, Harker, Daniel, Harpold, Ari-Matti, Harri, Karl, Harshman, Donald, Hassler, Harri, Haukka, Alex, Hayes, Ken, Herkenhoff, Paul, Herrera, Sebastian, Hettrich, Ezat, Heydari, Victoria, Hipkin, Tori, Hoehler, Jeff, Hollingsworth, Judy, Hudgins, Wesley, Huntress, Joel, Hurowitz, Stubbe, Hviid, Karl, Iagnemma, Steve, Indyk, Guy, Israël, Ryan, Jackson, Samantha, Jacob, Bruce, Jakosky, Elsa, Jensen, Jaqueline Kløvgaard, Jensen, Jeffrey, Johnson, Micah, Johnson, Steve, Johnstone, Andrea, Jones, Jonathan, Joseph, Insoo, Jun, Linda, Kah, Henrik, Kahanpää, Melinda, Kahre, Natalya, Karpushkina, Wayne, Kasprzak, Janne, Kauhanen, Leslie, Keely, Osku, Kemppinen, Didier, Keymeulen, Myung-Hee, Kim, Kjartan, Kinch, Penny, King, Laurel, Kirkland, Gary, Kocurek, Asmus, Koefoed, Jan, Köhler, Onno, Kortmann, Alexander, Kozyrev, Jill, Krezoski, Daniel, Krysak, Ruslan, Kuzmin, Jean Luc, Lacour, Vivian, Lafaille, Yves, Langevin, Nina, Lanza, Jeremie, Lasue, Stéphane, Le Mouélic, Ella Mae, Lee, Qiu-Mei, Lee, David, Lees, Matthew, Lefavor, Mark, Lemmon, Alain, Lepinette Malvitte, Richard, Léveillé, Éric, Lewin-Carpintier, Kevin, Lewis, Shuai, Li, Leslie, Lipkaman, Cynthia, Little, Maxim, Litvak, Eric, Lorigny, Guenter, Lugmair, Angela, Lundberg, Eric, Lyness, Morten, Madsen, Justin, Maki, Alexey, Malakhov, Charles, Malespin, Michael, Malin, Nicolas, Mangold, Gérard, Manhes, Heidi, Manning, Geneviève, Marchand, Mercedes, Marín Jiménez, César, Martín García, Dave, Martin, Mildred, Martin, Jesús, Martínez-Frías, Javier, Martín-Soler, F Javier, Martín-Torres, Patrick, Mauchien, Sylvestre, Maurice, Amy, McAdam, Elaina, McCartney, Timothy, McConnochie, Emily, McCullough, Ian, McEwan, Christopher, McKay, Scott, McLennan, Sean, McNair, Noureddine, Melikechi, Pierre-Yves, Meslin, Michael, Meyer, Alissa, Mezzacappa, Hayden, Miller, Kristen, Miller, Ralph, Milliken, Douglas, Ming, Michelle, Minitti, Michael, Mischna, Igor, Mitrofanov, Jeff, Moersch, Maxim, Mokrousov, Antonio, Molina Jurado, John, Moores, Luis, Mora-Sotomayor, John Michael, Morookian, Richard, Morris, Shaunna, Morrison, Reinhold, Mueller-Mellin, Jan-Peter, Muller, Guillermo, Muñoz Caro, Marion, Nachon, Sara, Navarro López, Rafael, Navarro-González, Kenneth, Nealson, Ara, Nefian, Tony, Nelson, Megan, Newcombe, Claire, Newman, Horton, Newsom, Sergey, Nikiforov, Brian, Nixon, Eldar, Noe Dobrea, Thomas, Nolan, Dorothy, Oehler, Ann, Ollila, Timothy, Olson, Miguel Ángel, de Pablo Hernández, Alexis, Paillet, Etienne, Pallier, Marisa, Palucis, Timothy, Parker, Yann, Parot, Kiran, Patel, Mark, Paton, Gale, Paulsen, Alex, Pavlov, Betina, Pavri, Verónica, Peinado-González, Laurent, Peret, Rene, Perez, Glynis, Perrett, Joe, Peterson, Cedric, Pilorget, Patrick, Pinet, Jorge, Pla-García, Ianik, Plante, Franck, Poitrasson, Jouni, Polkko, Radu, Popa, Liliya, Posiolova, Arik, Posner, Irina, Pradler, Benito, Prats, Vasily, Prokhorov, Sharon Wilson, Purdy, Eric, Raaen, Leon, Radziemski, Scot, Rafkin, Miguel, Ramos, Elizabeth, Rampe, François, Raulin, Michael, Ravine, Günther, Reitz, Nilton, Rennó, Melissa, Rice, Mark, Richardson, François, Robert, Kevin, Robertson, José Antonio, Rodriguez Manfredi, Julio J, Romeral-Planelló, Scott, Rowland, David, Rubin, Muriel, Saccoccio, Andrew, Salamon, Jennifer, Sandoval, Anton, Sanin, Sara Alejandra, Sans Fuentes, Lee, Saper, Philippe, Sarrazin, Violaine, Sautter, Hannu, Savijärvi, Juergen, Schieber, Mariek, Schmidt, Walter, Schmidt, Daniel, Scholes, Marcel, Schoppers, Susanne, Schröder, Susanne, Schwenzer, Eduardo, Sebastian Martinez, Aaron, Sengstacken, Ruslan, Shterts, Kirsten, Siebach, Tero, Siili, Jeff, Simmonds, Jean-Baptiste, Sirven, Susie, Slavney, Ronald, Sletten, Michael, Smith, Pablo, Sobrón Sánchez, Nicole, Spanovich, John, Spray, Steven, Squyres, Katie, Stack, Fabien, Stalport, Thomas, Stein, Noel, Stewart, Susan Louise Svane, Stipp, Kevin, Stoiber, Ed, Stolper, Bob, Sucharski, Rob, Sullivan, Roger, Summons, Dawn, Sumner, Vivian, Sun, Kimberley, Supulver, Brad, Sutter, Cyril, Szopa, Florence, Tan, Christopher, Tate, Samuel, Teinturier, Inge, ten Kate, Peter, Thomas, Lucy, Thompson, Robert, Tokar, Mike, Toplis, Josefina, Torres Redondo, Melissa, Trainer, Allan, Treiman, Vladislav, Tretyakov, Roser, Urqui-O'Callaghan, Jason, Van Beek, Tessa, Van Beek, Scott, VanBommel, David, Vaniman, Alexey, Varenikov, Ashwin, Vasavada, Paulo, Vasconcelos, Edward, Vicenzi, Andrey, Vostrukhin, Mary, Voytek, Meenakshi, Wadhwa, Jennifer, Ward, Eddie, Weigle, Danika, Wellington, Frances, Westall, Roger Craig, Wiens, Mary Beth, Wilhelm, Amy, Williams, Joshua, Williams, Rebecca, Williams, Richard B, Williams, Mike, Wilson, Robert, Wimmer-Schweingruber, Mike, Wolff, Mike, Wong, James, Wray, Megan, Wu, Charles, Yana, Albert, Yen, Aileen, Yingst, Cary, Zeitlin, Robert, Zimdar, and María-Paz, Zorzano Mier

Subjects
Atmosphere, Martian, chemistry.chemical_compound, Multidisciplinary, Meteorite, chemistry, Stable isotope ratio, Sample Analysis at Mars, Carbonate, Mars Exploration Program, Atmosphere of Mars, Astrobiology
Abstract

Mars' Atmosphere from Curiosity The Sample Analysis at Mars (SAM) instrument on the Curiosity rover that landed on Mars in August last year is designed to study the chemical and isotopic composition of the martian atmosphere. Mahaffy et al. (p. 263 ) present volume-mixing ratios of Mars' five major atmospheric constituents (CO 2 , Ar, N 2 , O 2 , and CO) and isotope measurements of 40 Ar/ 36 Ar and C and O in CO 2 , based on data from one of SAM's instruments, obtained between 31 August and 21 November 2012. Webster et al. (p. 260 ) used data from another of SAM's instruments obtained around the same period to determine isotope ratios of H, C, and O in atmospheric CO 2 and H 2 O. Agreement between the isotopic ratios measured by SAM with those of martian meteorites, measured in laboratories on Earth, confirms the origin of these meteorites and implies that the current atmospheric reservoirs of CO 2 and H 2 O were largely established after the period of early atmospheric loss some 4 billion years ago.

Published
2013

17. The ChemCam Instrument Suite on the Mars Science Laboratory (MSL) Rover: Body Unit and Combined System Tests

Author

Roger C. Wiens, Sylvestre Maurice, Bruce Barraclough, Muriel Saccoccio, Walter C. Barkley, James F. Bell, Steve Bender, John Bernardin, Diana Blaney, Jennifer Blank, Marc Bouyé, Nathan Bridges, Nathan Bultman, Phillippe Caïs, Robert C. Clanton, Benton Clark, Samuel Clegg, Agnes Cousin, David Cremers, Alain Cros, Lauren DeFlores, Dorothea Delapp, Robert Dingler, Claude D’Uston, M. Darby Dyar, Tom Elliott, Don Enemark, Cecile Fabre, Mike Flores, Olivier Forni, Olivier Gasnault, Thomas Hale, Charles Hays, Ken Herkenhoff, Ed Kan, Laurel Kirkland, Driss Kouach, David Landis, Yves Langevin, Nina Lanza, Frank LaRocca, Jeremie Lasue, Joseph Latino, Daniel Limonadi, Chris Lindensmith, Cynthia Little, Nicolas Mangold, Gerard Manhes, Patrick Mauchien, Christopher McKay, Ed Miller, Joe Mooney, Richard V. Morris, Leland Morrison, Tony Nelson, Horton Newsom, Ann Ollila, Melanie Ott, Laurent Pares, René Perez, Franck Poitrasson, Cheryl Provost, Joseph W. Reiter, Tom Roberts, Frank Romero, Violaine Sautter, Steven Salazar, John J. Simmonds, Ralph Stiglich, Steven Storms, Nicolas Striebig, Jean-Jacques Thocaven, Tanner Trujillo, Mike Ulibarri, David Vaniman, Noah Warner, Rob Waterbury, Robert Whitaker, James Witt, and Belinda Wong-Swanson

Subjects
010401 analytical chemistry, 010502 geochemistry & geophysics, 01 natural sciences, 0104 chemical sciences, 0105 earth and related environmental sciences
Published
2012

18. Pits on Jupiter-family Comets and the Age of Cometary Surfaces

Author

Aurélie Guilbert-Lepoutre, Selma Benseguane, Laurine Martinien, Jérémie Lasue, Sébastien Besse, Björn Grieger, and Arnaud Beth

Subjects
Short period comets, Comet nuclei, Comet surfaces, Theoretical models, Astronomy, QB1-991
Abstract

Large and deep depressions, also known as pits, are observed at the surface of all Jupiter-family comets (JFCs) imaged by spacecraft missions. They offer the opportunity to glimpse the subsurface characteristics of comet nuclei and study the complex interplay between surface structures and cometary activity. This work investigates the evolution of pits at the surface of 81P/Wild 2, 9P/Tempel 1, and 103P/Hartley 2, in continuation of the work by Benseguane et al. on 67P/Churyumov–Gerasimenko. Pits are selected across the surface of each nucleus, and high-resolution shape models are used to compute the energy they receive. A thermal evolution model is applied to constrain how cometary activity sustained under current illumination conditions could modify them. Similar to what was found for 67P, we show that erosion resulting from water-driven activity is primarily controlled by seasonal patterns that are unique to each comet as a consequence of their shape and rotational properties. However, progressive erosion sustained after multiple perihelion passages is not able to carve any of the observed pits. Instead, cometary activity tends to erase sharp morphological features; they become wider and shallower over time. Our results reinforce the evolutionary sequence evidenced from independent measurables to transform “young” cometary surfaces, with sharp surface topography prone to outbursts, into “old” cometary surfaces. Finally, we suggest that the mechanism at the origin of the pits on JFCs should be able to carve these structures in a region of the solar system where water ice does not sublimate; the Centaur phase thus appears critical to understand JFC surface properties.

Published
2023
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20. LEAVING GLEN TORRIDON: BEDROCK GEOCHEMISTRY MEASURED BY CHEMCAM EN ROUTE TO THE SULFATE UNIT OF GALE CRATER

Author

Erwin Dehouck, Agnes Cousin, Nicolas Mangold, Jens Frydenvang, Olivier Gasnault, William Rapin, Olivier Forni, Patrick Gasda, Gael David, Gwénaël CARAVACA, Jeremie Lasue, Pierre-Yves Meslin, Candice Bedford, Lanza, Nina L., Valerie Fox, Kristen Bennett, Alexander Bryk, Sylvestre Maurice, Wiens, Roger C., 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), 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), University of Copenhagen = Københavns Universitet (UCPH), Los Alamos National Laboratory (LANL), Lunar and Planetary Institute [Houston] (LPI), Department of Earth Sciences [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Astrogeology Science Center [Flagstaff], United States Geological Survey [Reston] (USGS), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Lunar and Planetary Institute, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), University of Copenhagen = Københavns Universitet (KU), University of California [Berkeley], and University of California-University of California

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, ChemCam, [SDU]Sciences of the Universe [physics], [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, bedrock, Glen Torridon, Gale crater, geochemistry
Abstract

International audience; Since January 2019, the Mars Science Laboratory (MSL) rover Curiosity has been exploring the Glen Torridon (GT) region of Gale crater, which corresponds to the topographic trough between the Vera Rubin ridge and the Greenheugh pediment (Fig. 1). From orbit, this region stands out due to the rela-tively strong near-infrared signatures of clay minerals [1,2]. The data collected on the ground by Curiosity have allowed the MSL team to confirm and quantify the presence of these clay minerals [3], to characterize their organic content [4], and to document in detail their geochemical and sedimentological settings [5].In particular, the bedrock chemistry measured by ChemCam shows elevated values of the Chemical Index of Alteration (CIA) throughout most of Glen Torridon [6,7], which indicates an open-system type of alteration [8]. In addition, the ChemCam observations suggest the presence of illite in the fine-grained rocks [9] and reveal a possible relationship between grain size and geochemical variations [10]. Finally, they show that the light-toned rocks located just below the uncon-formity at the base of the Greenheugh pediment (and drilled at Hutton; Fig. 1) are associated with “anoma-lous” bedrock compositions that may be related to a late-stage diagenetic event at Gale [7].Here, we report the findings of the ChemCam instrument during the last stretch of the GT campaign, from Bloodstone Hill to the Sands of Forvie (Fig. 1). At the conference, we will also present the data acquired in early 2021, as Curiosity approaches the transition into the sulfate-bearing unit.

21. K-Rich Rubbly Bedrock at Glen Torridon, Gale Crater, Mars: Investigating the Possible Presence of Illite

Author

Agnes Cousin, Matthieu Desjardins, Erwin Dehouck, Olivier Forni, Gael David, Gilles Berger, Gwénaël Caravaca, Pierre-Yves Meslin, Jeremie Lasue, Ollila, Ann M., William Rapin, Patrick Gasda, Sylvestre Maurice, Olivier Gasnault, Wiens, Roger C., 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), Institut Polytechnique LaSalle Beauvais, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-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), Los Alamos National Laboratory (LANL), Lunar and Planetary Institute, 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), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and 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)

Subjects
illite, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, potassium, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Glen Torridon, Gale crater, geochemistry
Abstract

International audience; Introduction: The Curiosity rover reached the Glen Torridon (GT) area around sol 2300 (January 2019). GT is known to display relatively strong and extensive smectite signatures from orbit [1]. During the last two years of exploring this area, Curiosity has revealed variations in chemical compositions correlated with bedrock facies [2-4]. The spatially dominant type of rock in the lowermost part of GT (which is a lateral continuation of the Jura member) is described as the "rubbly" bedrock because it outcrops as small pieces of bedrock embedded in soil. The rubbly bedrock is composed of finely-laminated mudstones and is characterized by enrichments in K2O and SiO2 [3], whereas the slabs of coherent bedrock adjacent to it are lower in K2O but enriched in MgO [3]. Another mudstone layer with a low MgO/high K2O type of composition is also observed in the overlying Knockfarril Hill member, between Glen Etive and Central Butte. X-ray diffraction (XRD) analyses performed by the CheMin instrument showed that the Jura coherent bedrock contains ~30 wt% of Fe-smectites [5]. However, no XRD analysis was performed on the rubbly bedrock, and the discussion below is thus based solely on elemental compositions measured by ChemCam [6,7]. The objective of this work is to discuss clues regarding the mineralogy of the GT rubbly bedrock: in particular whether the enrichment in K2O is related to partial illitization of the clay minerals, or to a mixing with K-feldspars? Elevated K2O abundances were previously observed in the Kimberley area [8-9], on the floor of Aeolis Palus [10], where CheMin results showed an associated enrichment in K-feldspar (sanidine) [9]. K-feldspars were also observed in igneous rocks such as trachytes [11,12]. In this study, data from the rubbly bedrock of GT are therefore compared to data from Kimberley and from the trachytic igneous rocks observed at Bradbury. Some plagioclase-rich igneous rocks are also used for comparison [12]. Methodology: ChemCam uses the LIBS technique to perform remote chemical analyzes [6,7,12]. The laser beam (300-500 µm, [13]) is large enough that it mostly samples mixtures of mineral phases (as opposed to pure phases), especially in mudstones. Therefore, we used trends in elemental ratios to interpret the mineralogy of the rocks. Compositions with a sum of oxides

22. Géochimie des roches sédimentaires du cratère Gale : implications pour l'altération aqueuse sur Mars

Author

Erwin Dehouck, Nicolas Mangold, Agnès Cousin, Olivier Gasnault, Olivier Forni, Gaël David, Jeremie Lasue, Pierre-Yves Meslin, William Rapin, Sylvestre Maurice, 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 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), and SGF, CNRS, Laboratoire de Géologie de Lyon ou l’étude de la Terre, des planètes et de l’environnement

Subjects
altération aqueuse, minéraux argileux, [SDU]Sciences of the Universe [physics], géochimie, smectites, Mars, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

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