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1. ESTIMATE OF DTM DEGRADATION DUE TO IMAGE COMPRESSION FOR THE STEREO CAMERA OF THE BEPICOLOMBO MISSION

Author

C. Re, E. Simioni, G. Cremonese, R. Roncella, G. Forlani, Y. Langevin, V. Da Deppo, G. Naletto, and G. Salemi

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

The great amount of data that will be produced during the imaging of Mercury by the stereo camera (STC) of the BepiColombo mission needs a compromise with the restrictions imposed by the band downlink that could drastically reduce the duration and frequency of the observations. The implementation of an on-board real time data compression strategy preserving as much information as possible is therefore mandatory. The degradation that image compression might cause to the DTM accuracy is worth to be investigated. During the stereo-validation procedure of the innovative STC imaging system, several image pairs of an anorthosite sample and a modelled piece of concrete have been acquired under different illumination angles. This set of images has been used to test the effects of the compression algorithm (Langevin and Forni, 2000) on the accuracy of the DTM produced by dense image matching. Different configurations taking in account at the same time both the illumination of the surface and the compression ratio, have been considered. The accuracy of the DTMs is evaluated by comparison with a high resolution laser-scan acquisition of the same targets. The error assessment included also an analysis on the image plane indicating the influence of the compression procedure on the image measurements.

Published
2016
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2. Moonraker -- Enceladus Multiple Flyby Mission

Author

O. Mousis, A. Bouquet, Y. Langevin, N. André, H. Boithias, G. Durry, F. Faye, P. Hartogh, J. Helbert, L. Iess, S. Kempf, A. Masters, F. Postberg, J.-B. Renard, P. Vernazza, A. Vorburger, P. Wurz, D. H. Atkinson, S. Barabash, M. Berthomier, J. Brucato, M. Cable, J. Carter, S. Cazaux, A. Coustenis, G. Danger, V. Dehant, T. Fornaro, P. Garnier, T. Gautier, O. Groussin, L. Z. Hadid, J.-C. Ize, I. Kolmasova, J.-P. Lebreton, S. Le Maistre, E. Lellouch, J. I. Lunine, K. E. Mandt, Z. Martins, D. Mimoun, Q. Nenon, G. M. Muñoz Caro, P. Rannou, H. Rauer, P. Schmitt-Kopplin, A. Schneeberger, M. Simons, K. Stephan, T. Van Hoolst, J. Vaverka, M. Wieser, L. Wörner, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), UCL - SST/ELI/ELIC - Earth & Climate, Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), 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 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), Airbus Defence and Space [Les Mureaux], ASTRIUM, Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Dipartimento di Ingegneria Meccanica e Aerospaziale [Roma La Sapienza] (DIMA), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Imperial College London, Institute of Geological Sciences [Berlin], Department of Earth Sciences [Berlin], Free University of Berlin (FU)-Free University of Berlin (FU), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), 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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Physics Institute [Bern], University of Bern, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Swedish Institute of Space Physics [Kiruna] (IRF), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Faculty of Aerospace Engineering [Delft], Delft University of Technology (TU Delft), Leiden Observatory [Leiden], Universiteit Leiden, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), Royal Observatory of Belgium [Brussels] (ROB), 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), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Faculty of Mathematics and Physics [Praha/Prague], Charles University [Prague] (CU), Department of Astronomy [Ithaca], Cornell University [New York], Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Centro de Quimica Estrutural (CQE), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max-Planck-Institut für Extraterrestrische Physik (MPE), Seismological Laboratory, California Institute of Technology, California Institute of Technology (CALTECH), and DLR In­sti­tute of Quan­tum Tech­nolo­gies

Subjects
530 Physics, ISOTOPOLOGUES, MU-M, FOS: Physical sciences, Saturnian satellites, Astronomy & Astrophysics, moon, Enceladus, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Earth and Planetary Sciences (miscellaneous), Interdisciplinary astronomy, INTERIOR STRUCTURE, ION, Habitable planets, Instrumentation and Methods for Astrophysics (astro-ph.IM), CALIBRATION, Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, SPECTROSCOPY, GRAVITY-FIELD, 520 Astronomy, 500 Naturwissenschaften und Mathematik::520 Astronomie::520 Astronomie und zugeordnete Wissenschaften, Astronomy and Astrophysics, CASSINI, Astrobiology, 620 Engineering, PLUME, Geophysics, Saturn, [SDU]Sciences of the Universe [physics], Space and Planetary Science, MASS-SPECTROMETER, Physical Sciences, Ocean planets, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Enceladus, an icy moon of Saturn, possesses an internal water ocean and jets expelling ocean material into space. Cassini investigations indicated that the subsurface ocean could be a habitable environment having a complex interaction with the rocky core. Further investigation of the composition of the plume formed by the jets is necessary to fully understand the ocean, its potential habitability, and what it tells us about Enceladus' origin. Moonraker has been proposed as an ESA M-class mission designed to orbit Saturn and perform multiple flybys of Enceladus, focusing on traversals of the plume. The proposed Moonraker mission consists of an ESA-provided platform, with strong heritage from JUICE and Mars Sample Return, and carrying a suite of instruments dedicated to plume and surface analysis. The nominal Moonraker mission has a duration of 13.5 years. It includes a 23-flyby segment with 189 days allocated for the science phase, and can be expanded with additional segments if resources allow. The mission concept consists in investigating: i) the habitability conditions of present-day Enceladus and its internal ocean, ii) the mechanisms at play for the communication between the internal ocean and the surface of the South Polar Terrain, and iii) the formation conditions of the moon. Moonraker, thanks to state-of-the-art instruments representing a significant improvement over Cassini's payload, would quantify the abundance of key species in the plume, isotopic ratios, and physical parameters of the plume and the surface. Such a mission would pave the way for a possible future landed mission., Accepted for publication in The Planetary Science Journal

Published
2022
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3. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

Author

F. Capaccioni, A. Coradini, G. Filacchione, S. Erard, G. Arnold, P. Drossart, M. C. De Sanctis, D. Bockelee-Morvan, M. T. Capria, F. Tosi, C. Leyrat, B. Schmitt, E. Quirico, P. Cerroni, V. Mennella, A. Raponi, M. Ciarniello, T. McCord, L. Moroz, E. Palomba, E. Ammannito, M. A. Barucci, G. Bellucci, J. Benkhoff, J. P. Bibring, A. Blanco, M. Blecka, R. Carlson, U. Carsenty, L. Colangeli, M. Combes, M. Combi, J. Crovisier, T. Encrenaz, C. Federico, U. Fink, S. Fonti, W. H. Ip, P. Irwin, R. Jaumann, E. Kuehrt, Y. Langevin, G. Magni, S. Mottola, V. Orofino, P. Palumbo, G. Piccioni, U. Schade, F. Taylor, D. Tiphene, G. P. Tozzi, P. Beck, N. Biver, L. Bonal, J.-Ph. Combe, D. Despan, E. Flamini, S. Fornasier, A. Frigeri, D. Grassi, M. Gudipati, A. Longobardo, K. Markus, F. Merlin, R. Orosei, G. Rinaldi, K. Stephan, M. Cartacci, A. Cicchetti, S. Giuppi, Y. Hello, F. Henry, S. Jacquinod, R. Noschese, G. Peter, R. Politi, J. M. Reess, and A. Semery

Published
2015
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4. SIMBIO-SYS: Scientific Cameras and Spectrometer for the BepiColombo Mission

Author

Marilena Amoroso, Francesca Esposito, Giancarlo Bellucci, Y. Langevin, Marco Baroni, Océane Barraud, Francesca Altieri, Giacomo Colombatti, Michael Mendillo, M. I. Blecka, M. T. Capria, Romolo Politi, Ernesto Palomba, Pasquale Palumbo, Olivier Forni, Gianfranco Forlani, E. Flamini, Francesca Ferri, P. Borin, Lionel Wilson, Andrea Cicchetti, Vito Mennella, Carlo Bettanini, Riccardo Paolinetti, Alice Lucchetti, Davide Perna, Nicolas Thomas, Marcello Fulchignoni, V. Della Corte, Maria Sgavetti, Daniela Fantinel, M. El yazidi, A. Doressoundiram, Luigi Ferranti, Simone Marchi, John Robert Brucato, T. Van Hoolst, Cedric Leyrat, Sebastien Besse, Stéphane Erard, Elena Martellato, Y. Li, Diego Turrini, Francesco Marzari, W-H. Ip, Maurizio Pajola, Cristian Carli, Raffaella Noschese, Matteo Massironi, Sabrina Ferrari, Alessio Aboudan, Giuseppe Salemi, I. Ficai Veltroni, Lorenza Giacomini, Karri Muinonen, Emanuele Simioni, Jessica Flahaut, Priscilla Cerroni, Mathieu Vincendon, V. Da Deppo, Alessandra Slemer, L. M. Lara, M. C. De Sanctis, Raffaele Mugnuolo, M. Dami, Francesca Zambon, G. Piccioni, L. Guzzetta, Fabrizio Capaccioni, Giampiero Naletto, E. Mazzotta Epifani, G. Aroldi, Andrea Turella, Michele Zusi, Maurizio Rossi, Stefano Debei, Gabriele Cremonese, A. Barucci, Johannes Benkhoff, Gloria Tognon, Cristina Re, François Poulet, Donato Borrelli, Sonia Fornasier, Valentina Galluzzi, Gianrico Filacchione, Leonardo Tommasi, François Leblanc, Laurent Jorda, Lucia Marinangeli, Roberto Ragazzoni, V. Carlier, Alessandra Rotundi, N. Bott, Luigi Colangeli, Klaus Gwinner, Cremonese, G., Capaccioni, F., Capria, M. T., Doressoundiram, A., Palumbo, P., Vincendon, M., Massironi, M., Debei, S., Zusi, M., Altieri, F., Amoroso, M., Aroldi, G., Baroni, M., Barucci, A., Bellucci, G., Benkhoff, J., Besse, S., Bettanini, C., Blecka, M., Borrelli, D., Brucato, J. R., Carli, C., Carlier, V., Cerroni, P., Cicchetti, A., Colangeli, L., Dami, M., Da Deppo, V., Della Corte, V., De Sanctis, M. C., Erard, S., Esposito, F., Fantinel, D., Ferranti, L., Ferri, F., Ficaiveltroni, I., Filacchione, G., Flamini, E., Forlani, G., Fornasier, S., Forni, O., Fulchignoni, M., Galluzzi, V., Gwinner, K., Ip, W., Jorda, L., Langevin, Y., Lara, L., Leblanc, F., Leyrat, C., Li, Y., Marchi, S., Marinangeli, L., Marzari, F., Mazzottaepifani, E., Mendillo, M., Mennella, V., Mugnuolo, R., Muinonen, K., Naletto, G., Noschese, R., Palomba, E., Paolinetti, R., Perna, D., Piccioni, G., Politi, R., Poulet, F., Ragazzoni, R., Re, C., Rossi, M., Rotundi, A., Salemi, G., Sgavetti, M., Simioni, E., Thomas, N., Tommasi, L., Turella, A., Van Hoolst, T., Wilson, L., Zambon, F., Aboudan, A., Barraud, O., Bott, N., Borin, P., Colombatti, G., Elyazidi, M., Ferrari, S., Flahaut, J., Giacomini, L., Guzzetta, L., Lucchetti, A., Martellato, E., Pajola, M., Slemer, A., Tognon, G., Turrini, D., INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), 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), Dipartimento di Fisica 'Ettore Pancini', University of Naples Federico II = Università degli studi di Napoli Federico II, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Dipartimento di Geoscienze [Padova], Università degli Studi di Padova = University of Padua (Unipd), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Agenzia Spaziale Italiana (ASI), Leonardo SpA, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), European Space Astronomy Centre (ESAC), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), INAF - Osservatorio Astronomico di Capodimonte (OAC), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Department og Engineering and Architecture [Parma] (DIA), Università degli studi di Parma = University of Parma (UNIPR), 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), DLR Institute of Planetary Research, German Aerospace Center (DLR), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), HELIOS - 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), Suzhou Vocational University, Southwest Research Institute [Boulder] (SwRI), International Research School of Planetary Sciences [Pescara] (IRSPS), Dipartimento di Fisica e Astronomia 'Galileo Galilei', INAF - Osservatorio Astronomico di Roma (OAR), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Finnish Geospatial Research Institute (FGI), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), Department of Cultural Heritage [Padova], Dipartimento di Scienze della Terra [Parma], Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Royal Observatory of Belgium [Brussels] (ROB), Environmental Sciences [Lancaster], Lancaster University, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), 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), Università degli studi di Napoli Federico II, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universita degli Studi di Padova, European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), University of Parma = Università degli studi di Parma [Parme, Italie], 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), 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), University of Helsinki-University of Helsinki, Universita degli studi di Napoli 'Parthenope' [Napoli], Universität Bern [Bern], and Agenzia Spaziale Italiana

Subjects
010504 meteorology & atmospheric sciences, Computer science, BepiColombo, MPO, Astronomy & Astrophysics, INFRARED REFLECTANCE SPECTRA, 01 natural sciences, 7. Clean energy, Spectrometer, MECHANISMS, law.invention, Orbiter, EXPLOSIVE VOLCANISM, law, 0103 physical sciences, instrument, Spectral resolution, 010303 astronomy & astrophysics, Image resolution, BASIN, 0105 earth and related environmental sciences, Remote sensing, SIMBIO-SYS, ONBOARD, Science & Technology, SPECTROSCOPY, GRAVITY-FIELD, 520 Astronomy, Hyperspectral imaging, MERCURYS SURFACE, Astronomy and Astrophysics, Spectral bands, Mercury, 620 Engineering, HOLLOWS, Imageur, Stereo imaging, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physical Sciences, MESSENGER, Stereo camera
Abstract

Full list of authors: Cremonese, G.; Capaccioni, F.; Capria, M. T.; Doressoundiram, A.; Palumbo, P.; Vincendon, M.; Massironi, M.; Debei, S.; Zusi, M.; Altieri, F.; Amoroso, M.; Aroldi, G.; Baroni, M.; Barucci, A.; Bellucci, G.; Benkhoff, J.; Besse, S.; Bettanini, C.; Blecka, M.; Borrelli, D.; Brucato, J. R.; Carli, C.; Carlier, V.; Cerroni, P.; Cicchetti, A.; Colangeli, L.; Dami, M.; Da Deppo, V.; Della Corte, V.; De Sanctis, M. C.; Erard, S.; Esposito, F.; Fantinel, D.; Ferranti, L.; Ferri, F.; Ficai Veltroni, I.; Filacchione, G.; Flamini, E.; Forlani, G.; Fornasier, S.; Forni, O.; Fulchignoni, M.; Galluzzi, V.; Gwinner, K.; Ip, W.; Jorda, L.; Langevin, Y.; Lara, L.; Leblanc, F.; Leyrat, C.; Li, Y.; Marchi, S.; Marinangeli, L.; Marzari, F.; Mazzotta Epifani, E.; Mendillo, M.; Mennella, V.; Mugnuolo, R.; Muinonen, K.; Naletto, G.; Noschese, R.; Palomba, E.; Paolinetti, R.; Perna, D.; Piccioni, G.; Politi, R.; Poulet, F.; Ragazzoni, R.; Re, C.; Rossi, M.; Rotundi, A.; Salemi, G.; Sgavetti, M.; Simioni, E.; Thomas, N.; Tommasi, L.; Turella, A.; Van Hoolst, T.; Wilson, L.; Zambon, F.; Aboudan, A.; Barraud, O.; Bott, N.; Borin, P.; Colombatti, G.; El Yazidi, M.; Ferrari, S.; Flahaut, J.; Giacomini, L.; Guzzetta, L.; Lucchetti, A.; Martellato, E.; Pajola, M.; Slemer, A.; Tognon, G.; Turrini, D. -- This is an open access article, The SIMBIO-SYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument suite part of the scientific payload of the Mercury Planetary Orbiter for the BepiColombo mission, the last of the cornerstone missions of the European Space Agency (ESA) Horizon + science program. The SIMBIO-SYS instrument will provide all the science imaging capability of the BepiColombo MPO spacecraft. It consists of three channels: the STereo imaging Channel (STC), with a broad spectral band in the 400-950 nm range and medium spatial resolution (at best 58 m/px), that will provide Digital Terrain Model of the entire surface of the planet with an accuracy better than 80 m; the High Resolution Imaging Channel (HRIC), with broad spectral bands in the 400-900 nm range and high spatial resolution (at best 6 m/px), that will provide high-resolution images of about 20% of the surface, and the Visible and near-Infrared Hyperspectral Imaging channel (VIHI), with high spectral resolution (6 nm at finest) in the 400-2000 nm range and spatial resolution reaching 120 m/px, it will provide global coverage at 480 m/px with the spectral information, assuming the first orbit around Mercury with periherm at 480 km from the surface. SIMBIO-SYS will provide high-resolution images, the Digital Terrain Model of the entire surface, and the surface composition using a wide spectral range, as for instance detecting sulphides or material derived by sulphur and carbon oxidation, at resolutions and coverage higher than the MESSENGER mission with a full co-alignment of the three channels. All the data that will be acquired will allow to cover a wide range of scientific objectives, from the surface processes and cartography up to the internal structure, contributing to the libration experiment, and the surface-exosphere interaction. The global 3D and spectral mapping will allow to study the morphology and the composition of any surface feature. In this work, we describe the on-ground calibrations and the results obtained, providing an important overview of the instrument performances. The calibrations have been performed at channel and at system levels, utilizing specific setup in most of the cases realized for SIMBIO-SYS. In the case of the stereo camera (STC), it has been necessary to have a validation of the new stereo concept adopted, based on the push-frame. This work describes also the results of the Near-Earth Commissioning Phase performed few weeks after the Launch (20 October 2018). According to the calibration results and the first commissioning the three channels are working very well. © 2020, The Author(s)., We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0. The SIMBIO-SYS instrument has been developed by Leonardo under ASI contract I/054/10/0.

Published
2020
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5. Phyllosilicates on Mars and implications for early martian climate

Author

F, Poulet, J-P, Bibring, J F, Mustard, A, Gendrin, N, Mangold, Y, Langevin, R E, Arvidson, B, Gondet, C, Gomez, M, Berthé, S, Erard, O, Forni, N, Manaud, G, Poulleau, A, Soufflot, M, Combes, P, Drossart, T, Encrenaz, T, Fouchet, R, Melchiorri, G, Bellucci, F, Altieri, V, Formisano, S, Fonti, F, Capaccioni, P, Cerroni, A, Coradini, O, Korablev, V, Kottsov, N, Ignatiev, D, Titov, L, Zasova, P, Pinet, B, Schmitt, C, Sotin, E, Hauber, H, Hoffmann, R, Jaumann, U, Keller, F, Forget, Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and CRINON, Evelyne

Subjects
Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Climate, Iron, Mars, 01 natural sciences, Astrobiology, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 0103 physical sciences, Magnesium, Composition of Mars, Spacecraft, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Martian, Mineral hydration, Multidisciplinary, Mineral, Sulfates, Noachian, Water, Mars Exploration Program, Hydrogen-Ion Concentration, Space Flight, CRISM, 13. Climate action, Clay, Hesperian, Aluminum Silicates, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology, Geology
Abstract

The recent identification of large deposits of sulphates by remote sensing and in situ observations has been considered evidence of the past presence of liquid water on Mars. Here we report the unambiguous detection of diverse phyllosilicates, a family of aqueous alteration products, on the basis of observations by the OMEGA imaging spectrometer on board the Mars Express spacecraft. These minerals are mainly associated with Noachian outcrops, which is consistent with an early active hydrological system, sustaining the long-term contact of igneous minerals with liquid water. We infer that the two main families of hydrated alteration products detected-phyllosilicates and sulphates--result from different formation processes. These occurred during two distinct climatic episodes: an early Noachian Mars, resulting in the formation of hydrated silicates, followed by a more acidic environment, in which sulphates formed.

Published
2005
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6. The COMET experiment

Author

P. Salvetat, Y. Langevin, Janet Borg, B. Vassent, and J. P. Bibring

Subjects
Physics, Solar System, Interplanetary dust cloud, Impact crater, Meteoroid, Comet tail, Comet dust, Comet, Halley's Comet, General Earth and Planetary Sciences, Astronomy, Astrophysics, General Environmental Science
Abstract

— The COMET program is a program for the collection of micron to submicron interplanetary dust particles in low Earth orbits. Since collection takes place as the Earth crosses a given meteor stream, the particles are mainly of cometary origin. The grain remnants, located at their impact positions on high purity metallic collectors, are analysed in the laboratory for chemical and isotopical identification. The COMET-1 experiment took place in 1985 October, during encounter with the Draconid meteor stream, related to the Giacobini-Zinner comet. The fluence of extraterrestrial grains that had impacted our detectors was ∼10x higher than the value of the mean meteroid fluence at ∼1AU, which suggests that most of the grains originated from the Giacobini-Zinner comet. One of the most important results of their chemical analysis was that ∼90% of them are enriched in low Z elements (C and O have undoubedly been identified). They could contain a CHON phase similar to that observed in the close environment of Halley's nucleus. The first imagery of the grain remnants by field emission scanning electron microscopy suggests that they are very low density aggregates still present at the impacting positions which, in most cases, are very different from the impact craters observed for the same mean relative velocity for full grains of the same size. These results show that the COMET program has constituted an important step towards the analysis of cometary material and the understanding of the evolution of the early Solar System.

Published
1993
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8. The VESTA project: Combined studies of Mars and small bodies of the solar system

Author

Y. Langevin

Subjects
Atmospheric Science, Solar System, Spacecraft, business.industry, Comet, Vega, Mars landing, Aerospace Engineering, Astronomy, Astronomy and Astrophysics, Mars Exploration Program, Exploration of Mars, Astrobiology, Geophysics, Space and Planetary Science, Asteroid, General Earth and Planetary Sciences, business, Geology
Abstract

A mission to Mars and small solar system bodies is presently studied as a possible collaboration between INTERCOSMOS, CNES, ESA and eventually other participants. The VESTA concept, based on the same strategy as the successful VEGA mission, is more ambitious, as two spacecrafts separate soon after launch: a soviet spacecraft, dedicated to the study of Mars, and a spacecraft dedicated to the study of small bodies, under the responsibility of CNES and ESA. This spacecraft would use Mars gravity assists to visit up to 4 small bodies in less than 5 years. The mission is duplicated, which means that up to 8 small bodies could be studied (e.g. 6 main belt asteroids, 1 apollo-amor asteroid and 1 short period comet). Low relative velocities (

Published
1987
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9. Simulation laser d'impacts de particules de très grande vitesse

Author

J.-P. Bibring, M. Hallouin, J.P. Romain, Y. Langevin, F. Cottet, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, plasma production and heating by laser beam, laser pulse energy, mass loss ratio, plasma simulation, 010308 nuclear & particles physics, Al target, General Engineering, micrometeorites, laser simulation, hypervelocity impact, particle velocity, 01 natural sciences, pulsed Nd laser, plasma production, [PHYS.HIST]Physics [physics]/Physics archives, 0103 physical sciences, 010306 general physics, Geomorphology
Abstract

Le laser au néodyme du GRECO I.L.M. délivrant des impulsions de l'ordre de 100 J en quelques ns, nous a permis de simuler des impacts de micrométéorites silicatées de quelques dixièmes de μg, de vitesse comprise entre 5 et 45 km/s, sur une cible d'aluminium. Les cratères produits dans la cible sont hémisphériques, et le rapport Km, de la masse éjectée sur la masse de la particule incidente simulée, varie avec la vitesse d'impact Vp selon la loi Km = 1,17 V 1,52p.

Published
1983
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10. Microprobe studies of space weathering effects in extraterrestrial dust grains

Author

J. C. Dran, Y. Langevin, J. P. Duraud, M. Maurette, J. Klossa, Lorgeril, Jocelyne, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Auger electron spectroscopy, Microprobe, Materials science, 010504 meteorology & atmospheric sciences, Mineralogy, 010502 geochemistry & geophysics, 01 natural sciences, Space weathering, law.invention, Meteorite, law, Electron beam-induced deposition, Electron microscope, Environmental scanning electron microscope, 0105 earth and related environmental sciences, Cosmic dust
Abstract

A new microprobing procedure is used to characterize both the physical and chemical surface properties of individual grains on a microscale. In this procedure the same sub-micrometre sized area of a given grain is successively analysed with a high voltage electron microscope, an Auger microprobe and a field emission scanning electron microscope. This analytical technique has been applied to study lunar weathering effects and to tentatively infer the irradiation history of a Nerich fraction of the Orgueil meteorite.

Published
1977
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11. Composition of comet Halley dust particles from Vega observations

Author

J. Kissel, R. Z. Sagdeev, J. L. Bertaux, V. N. Angarov, J. Audouze, J. E. Blamont, K. Büchler, E. N. Evlanov, H. Fechtig, M. N. Fomenkova, H. von Hoerner, N. A. Inogamov, V. N. Khromov, W. Knabe, F. R. Krueger, Y. Langevin, V. B. Leonas, A. C. Levasseur-Regourd, G. G. Managadze, S. N. Podkolzin, V. D. Shapiro, S. R. Tabaldyev, B. V. Zubkov, Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), 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), National Academy of Sciences of Kyrgyz Republic, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), von Hoerner und Sulger Electronic Gmbh, MPI Consultant, Laboratoire Rene Bernas, and Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, Multidisciplinary, Comet dust, Halley's Comet, Comet, Astronomy, Interplanetary dust cloud, [SDU]Sciences of the Universe [physics], Comet nucleus, Mass spectrum, Particle, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Cosmic dust
Abstract

Mass spectra of cometary dust particles measured by the PIA dust particle analyzer aboard the Giotto spacecraft show some unexpected and striking features. First, small particles below 10 to the -14th g are much more abundant than anticipated by models. Second, most of the particles are rich in light elements such as H, C, N, and O, suggesting the validity of models that describe the cometary dust as including organic material. Third, the light elements specifically seem to have a low ratio of mass to volume. Three examples of original mass spectra showing typical compositions are given; these have been measured, and are compared with a computer-simulated mass spectrum.

Published
1986
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13. Exposed water ice on the nucleus of comet 67P/Churyumov-Gerasimenko

Author

Giancarlo Bellucci, Katrin Stephan, Yves Langevin, Sergio Fonti, G. Peter, Gianrico Filacchione, Ulrich Schade, G. P. Tozzi, Jacques Crovisier, Costanzo Federico, Eleonora Ammannito, M. I. Blecka, S. Jacquinod, Jean-Michel Reess, M. Cartacci, Michael R. Combi, Vito Mennella, Federico Tosi, Marcello Fulchignoni, Armando Blanco, Giuseppe Piccioni, Roberto Orosei, Bernard Schmitt, Andrea Longobardo, Giovanna Rinaldi, Ralf Jaumann, Vincenzo Orofino, Alessandra Migliorini, Andrea Raponi, Pierre Drossart, M. Combes, David Kappel, Mauro Ciarniello, D. Despan, Murthy S. Gudipati, C. Leyrat, T. Encrenaz, Ernesto Palomba, Andrea Cicchetti, Fabrizio Capaccioni, Michelangelo Formisano, Maria Teresa Capria, Romolo Politi, Dominique Bockelée-Morvan, Stefano Mottola, Enrico Flamini, Pierre Beck, L. Moroz, Gianfranco Magni, U. Fink, Eric Quirico, Fredric W. Taylor, Sonia Fornasier, J-Ph. Combe, F. Merlin, Jean-Pierre Bibring, N. Biver, M. C. De Sanctis, Florence Henry, Uri Carsenty, M. A. Barucci, Gabriele Arnold, Y. Hello, Patrick G. J. Irwin, R. W. Carlson, Wing-Huen Ip, E. Kuehrt, Kathrin Markus, Davide Grassi, S. Giuppi, Raffaella Noschese, Alessandro Frigeri, F. Mancarella, Stéphane Erard, Luigi Colangeli, Lydie Bonal, T. B. McCord, J. Benkhoff, D. Tiphene, Priscilla Cerroni, G., Filacchione, M. C., De Sancti, F., Capaccioni, A., Raponi, F., Tosi, M., Ciarniello, P., Cerroni, G., Piccioni, M. T., Capria, E., Palomba, G., Bellucci, S., Erard, D., Bockelee Morvan, C., Leyrat, G., Arnold, M. A., Barucci, M., Fulchignoni, B., Schmitt, E., Quirico, R., Jaumann, K., Stephan, A., Longobardo, V., Mennella, A., Migliorini, E., Ammannito, J., Benkhoff, J. P., Bibring, Blanco, Armando, M. I., Blecka, R., Carlson, U., Carsenty, L., Colangeli, M., Combe, M., Combi, J., Crovisier, P., Drossart, T., Encrenaz, C., Federico, U., Fink, Fonti, Sergio, W. H., Ip, P., Irwin, E., Kuehrt, Y., Langevin, G., Magni, T., Mccord, L., Moroz, S., Mottola, Orofino, Vincenzo, U., Schade, F., Taylor, D., Tiphene, G. P., Tozzi, P., Beck, N., Biver, L., Bonal, Combe, J. P. h., D., Despan, E., Flamini, M., Formisano, S., Fornasier, A., Frigeri, D., Grassi, M. S., Gudipati, D., Kappel, Mancarella, Francesca, K., Marku, F., Merlin, R., Orosei, G., Rinaldi, M., Cartacci, A., Cicchetti, S., Giuppi, Y., Hello, F., Henry, S., Jacquinod, J. M., Ree, R., Noschese, R., Politi, G., Peter, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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), Laboratoire de Physique et Mécanique Textiles (LPMT), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), 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]), German Aerospace Center (DLR), Deutsches Zentrum für Luft- und Raumfahrt (DLR), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), INAF - Osservatorio Astronomico di Capodimonte (OAC), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Instituto de Estudos Avançados (IEAV), Institut, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Dipartimento di Fisica, Università degli studi di Lecce, Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Department of Physics [Oxford], University of Oxford, Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], DLR Institute of Planetary Research, Department of Physics [Lecce], Università del Salento [Lecce], INAF - Osservatorio Astrofisico di Arcetri (OAA), 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), Alenia Aerospazio, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), JDS Uniphase/Cronos, USA, JDS Uniphase/Cronos, CNR-IASF, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Consiglio Nazionale delle Ricerche (CNR), 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), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-ENSITM-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), 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), European Space Agency (ESA), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk (PAN), University of Oxford [Oxford], 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), Centre National de la Recherche Scientifique (CNRS), Université de Lille-Université du Littoral Côte d'Opale-Centre National de la Recherche Scientifique (CNRS), ENSITM-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, 010504 meteorology & atmospheric sciences, Extraterrestrial Environment, Comet, Mineralogy, comet 67P, 01 natural sciences, water ice, Astrobiology, Diffusion, 0103 physical sciences, Rosetta, medicine, Diffusion (business), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Multidisciplinary, Meteoroid, Spectrum Analysis, Ice, food and beverages, Meteoroids, VIRTIS, Debris, Asteroids, Grain growth, medicine.anatomical_structure, 13. Climate action, comets and Kuiper belt Early solar system, Gases, Layering, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus, Water vapor
Abstract

Although water vapour is the main species observed in the coma of comet 67P/Churyumov–Gerasimenko1, 2 and water is the major constituent of cometary nuclei3, 4, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far5, 6. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far7, 8, 9. The nucleus of 67P/Churyumov–Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material10. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations6, 7, 8, 9. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers6, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust10 is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov–Gerasimenko11, 12 is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet’s formation.

Published
2016
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14. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

Author

Gabriele Arnold, Maria Teresa Capria, Y. Hello, Kathrin Markus, Vincenzo Orofino, A. Semery, Romolo Politi, Stéphane Erard, Roberto Orosei, Robert W. Carlson, Davide Grassi, M. Combes, J. Crovisier, Gianfranco Magni, Andrea Raponi, Michael R. Combi, Priscilla Cerroni, Yves Langevin, L. Moroz, Pierre Drossart, Ulrich Schade, G. P. Tozzi, Wing-Huen Ip, Luigi Colangeli, Fredric W. Taylor, Angioletta Coradini, J. Ph. Combe, Raffaella Noschese, Enrico Flamini, Giancarlo Bellucci, Ernesto Palomba, Sonia Fornasier, F. Merlin, Lydie Bonal, Andrea Longobardo, G. Peter, M. Cartacci, Alessandro Frigeri, Giuseppe Piccioni, Bernard Schmitt, Uwe Fink, Ralf Jaumann, Mauro Ciarniello, D. Despan, M. A. Barucci, Giovanna Rinaldi, Pierre Beck, M. C. De Sanctis, S. Giuppi, S. Jacquinod, Uri Carsenty, D. Bockelee-Morvan, Eric Quirico, Stefano Mottola, F. Henry, N. Biver, Jean-Pierre Bibring, Patrick G. J. Irwin, T. Encrenaz, Katrin Stephan, Andrea Cicchetti, Johannes Benkhoff, C. Leyrat, Gianrico Filacchione, D. Tiphene, J. M. Reess, T. B. McCord, Sergio Fonti, Costanzo Federico, Eleonora Ammannito, M. I. Blecka, Pasquale Palumbo, Armando Blanco, M. Gudipati, Fabrizio Capaccioni, Vito Mennella, Federico Tosi, E. Kuehrt, F., Capaccioni, A., Coradini, G., Filacchione, S., Erard, G., Arnold, P., Drossart, M. C., De Sancti, D., Bockelee Morvan, M. T., Capria, F., Tosi, C., Leyrat, B., Schmitt, E., Quirico, P., Cerroni, V., Mennella, A., Raponi, M., Ciarniello, T., Mccord, L., Moroz, E., Palomba, E., Ammannito, M. A., Barucci, G., Bellucci, J., Benkhoff, J. P., Bibring, Blanco, Armando, M., Blecka, R., Carlson, U., Carsenty, L., Colangeli, M., Combe, M., Combi, J., Crovisier, T., Encrenaz, C., Federico, U., Fink, Fonti, Sergio, W. H., Ip, P., Irwin, R., Jaumann, E., Kuehrt, Y., Langevin, G., Magni, S., Mottola, Orofino, Vincenzo, P., Palumbo, G., Piccioni, U., Schade, F., Taylor, D., Tiphene, G. P., Tozzi, P., Beck, N., Biver, L., Bonal, Combe, J. P. h., D., Despan, E., Flamini, S., Fornasier, A., Frigeri, D., Grassi, M., Gudipati, A., Longobardo, K., Marku, F., Merlin, R., Orosei, G., Rinaldi, K., Stephan, M., Cartacci, A., Cicchetti, S., Giuppi, Y., Hello, F., Henry, S., Jacquinod, R., Noschese, G., Peter, R., Politi, J. M., Ree, A., Semery, Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), 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), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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), Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk (PAN), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, German Aerospace Center (DLR), Department of Physics [Imperial College London], Imperial College London, Instituto de Estudos Avançados (IEAV), Institut, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Dipartimento di Fisica, Università degli studi di Lecce, Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], DLR Institute of Planetary Research, Department of Physics [Lecce], Università del Salento [Lecce], INAF - Osservatorio Astrofisico di Arcetri (OAA), 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), Alenia Aerospazio, JDS Uniphase/Cronos, USA, JDS Uniphase/Cronos, CNR-IASF, IASI (IASI), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Polska Akademia Nauk = Polish Academy of Sciences (PAN), NASA-California Institute of Technology (CALTECH), University of Oxford, 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), ITA, USA, GBR, FRA, DEU, TWN, NLD, and POL

Subjects
67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Opacity, Rosetta mission, VIRTIS, comets, Infrared, Comet, Imaging spectrometer, Astrophysics, 01 natural sciences, Astrobiology, comet, 0103 physical sciences, Spectral slope, Thermal, Rosetta, Rosetta mission, comets, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Multidisciplinary, Chemistry, Albedo, VIRTIS, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], organic-rich
Abstract

The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ −1 ), and the broad absorption feature in the 2.9-to-3.6–micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.

Published
2015
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15. The diurnal cycle of water ice on comet 67P/Churyumov-Gerasimenko

Author

DE SANCTIS, MARIA CRISTINA, CAPACCIONI, FABRIZIO, CIARNIELLO, Mauro, FILACCHIONE, GIANRICO, FORMISANO, Michelangelo, Mottola, S., RAPONI, Andrea, TOSI, Federico, Bockelée-Morvan, D., Erard, S., Leyrat, C., Schmitt, B., Ammannito, E., Arnold, G., Barucci, M. A., Combi, M., Capria, M. T., Cerroni, P., Ip, W. -H., Kuehrt, E., McCord, T. B., PALOMBA, Ernesto, Beck, P., Quirico, E., VIRTIS Team, PICCIONI, GIUSEPPE, BELLUCCI, Giancarlo, Fulchignoni, M., Jaumann, R., Stephan, K., Longobardo, A., MENNELLA, Vito, MIGLIORINI, Alessandra, Benkhoff, J., Bibring, J. P., Blanco, A., Blecka, M., Carlson, R., Carsenty, U., Colangeli, L., Combes, M., Crovisier, J., Drossart, P., Encrenaz, T., Federico, C., Fink, U., Fonti, S., Irwin, P., Langevin, Y., Magni, G., Moroz, L., Orofino, V., Schade, U., Taylor, F., Tiphene, D., Tozzi, G. P., Biver, N., Bonal, L., Combe, J. -Ph., Despan, D., Flamini, E., Fornasier, S., FRIGERI, ALESSANDRO, GRASSI, Davide, Gudipati, M. S., Mancarella, F., Markus, K., Merlin, F., OROSEI, ROBERTO, RINALDI, GIOVANNA, CARTACCI, MARCO, Cicchetti, A., GIUPPI, Stefano, Hello, Y., Henry, F., Jacquinod, S., Rees, J. M., NOSCHESE, RAFFAELLA, POLITI, ROMOLO, Peter, G., M. C., De Sancti, F., Capaccioni, M., Ciarniello, G., Filacchione, M., Formisano, S., Mottola, A., Raponi, F., Tosi, D., Bockele´e Morvan, S., Erard, C., Leyrat, B., Schmitt, E., Ammannito, G., Arnold, M. A., Barucci, M., Combi, M. T., Capria, P., Cerroni, W. H., Ip, E., Kuehrt, T. B., Mccord, E., Palomba, P., Beck, E., Quirico, G., Piccioni, G., Bellucci, M., Fulchignoni, R., Jaumann, K., Stephan, A., Longobardo, V., Mennella, A., Migliorini, J., Benkhoff, J. P., Bibring, Blanco, Armando, M., Blecka, R., Carlson, U., Carsenty, L., Colangeli, M., Combe, J., Crovisier, P., Drossart, T., Encrenaz, C., Federico, U., Fink, Fonti, Sergio, P., Irwin, Y., Langevin, G., Magni, L., Moroz, Orofino, Vincenzo, U., Schade, F., Taylor, D., Tiphene, G. P., Tozzi, N., Biver, L., Bonal, Combe, J. P. h., D., Despan, E., Flamini, S., Fornasier, A., Frigeri, D., Grassi, M. S., Gudipati, Mancarella, Francesca, K., Marku, F., Merlin, R., Orosei, G., Rinaldi, M., Cartacci, A., Cicchetti, S., Giuppi, Y., Hello, F., Henry, S., Jacquinod, J. M., Ree, R., Noschese, R., Politi, G., Peter, Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), DLR Institute of Planetary Research, German Aerospace Center (DLR), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Laboratoire de Sciences de la Terre, ITA, USA, GBR, FRA, DEU, TWN, NLD, POL, and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
67P/Churyumov-Gerasimenko, Time Factors, Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Comet, 01 natural sciences, water ice, Astrobiology, comet, Diurnal cycle, 0103 physical sciences, Sunrise, Water cycle, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Multidisciplinary, Meteoroid, Ice, Diurnal temperature variation, Temperature, food and beverages, Meteoroids, Environmental science, Volatilization, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Surface water, cycle of water ice, Water vapor
Abstract

Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasimenko have revealed that activity has a diurnal variation in intensity arising from changing insolation conditions. It was previously concluded that water vapour was generated in ice-rich subsurface layers with a transport mechanism linked to solar illumination, but that has not hitherto been observed. Periodic condensations of water vapour very close to, or on, the surface were suggested to explain short-lived outbursts seen near sunrise on comet 9P/Tempel 1. Here we report observations of water ice on the surface of comet 67P/Churyumov-Gerasimenko, appearing and disappearing in a cyclic pattern that follows local illumination conditions, providing a source of localized activity. This water cycle appears to be an important process in the evolution of the comet, leading to cyclical modification of the relative abundance of water ice on its surface.

Published
2015
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16. High-molecular-weight organic matter in the particles of comet 67P/Churyumov-Gerasimenko.

Author

Fray N, Bardyn A, Cottin H, Altwegg K, Baklouti D, Briois C, Colangeli L, Engrand C, Fischer H, Glasmachers A, Grün E, Haerendel G, Henkel H, Höfner H, Hornung K, Jessberger EK, Koch A, Krüger H, Langevin Y, Lehto H, Lehto K, Le Roy L, Merouane S, Modica P, Orthous-Daunay FR, Paquette J, Raulin F, Rynö J, Schulz R, Silén J, Siljeström S, Steiger W, Stenzel O, Stephan T, Thirkell L, Thomas R, Torkar K, Varmuza K, Wanczek KP, Zaprudin B, Kissel J, and Hilchenbach M

Abstract

The presence of solid carbonaceous matter in cometary dust was established by the detection of elements such as carbon, hydrogen, oxygen and nitrogen in particles from comet 1P/Halley. Such matter is generally thought to have originated in the interstellar medium, but it might have formed in the solar nebula-the cloud of gas and dust that was left over after the Sun formed. This solid carbonaceous material cannot be observed from Earth, so it has eluded unambiguous characterization. Many gaseous organic molecules, however, have been observed; they come mostly from the sublimation of ices at the surface or in the subsurface of cometary nuclei. These ices could have been formed from material inherited from the interstellar medium that suffered little processing in the solar nebula. Here we report the in situ detection of solid organic matter in the dust particles emitted by comet 67P/Churyumov-Gerasimenko; the carbon in this organic material is bound in very large macromolecular compounds, analogous to the insoluble organic matter found in the carbonaceous chondrite meteorites. The organic matter in meteorites might have formed in the interstellar medium and/or the solar nebula, but was almost certainly modified in the meteorites' parent bodies. We conclude that the observed cometary carbonaceous solid matter could have the same origin as the meteoritic insoluble organic matter, but suffered less modification before and/or after being incorporated into the comet.

Published
2016
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17. Exposed water ice on the nucleus of comet 67P/Churyumov-Gerasimenko.

Author

Filacchione G, De Sanctis MC, Capaccioni F, Raponi A, Tosi F, Ciarniello M, Cerroni P, Piccioni G, Capria MT, Palomba E, Bellucci G, Erard S, Bockelee-Morvan D, Leyrat C, Arnold G, Barucci MA, Fulchignoni M, Schmitt B, Quirico E, Jaumann R, Stephan K, Longobardo A, Mennella V, Migliorini A, Ammannito E, Benkhoff J, Bibring JP, Blanco A, Blecka MI, Carlson R, Carsenty U, Colangeli L, Combes M, Combi M, Crovisier J, Drossart P, Encrenaz T, Federico C, Fink U, Fonti S, Ip WH, Irwin P, Kuehrt E, Langevin Y, Magni G, McCord T, Moroz L, Mottola S, Orofino V, Schade U, Taylor F, Tiphene D, Tozzi GP, Beck P, Biver N, Bonal L, Combe JP, Despan D, Flamini E, Formisano M, Fornasier S, Frigeri A, Grassi D, Gudipati MS, Kappel D, Mancarella F, Markus K, Merlin F, Orosei R, Rinaldi G, Cartacci M, Cicchetti A, Giuppi S, Hello Y, Henry F, Jacquinod S, Reess JM, Noschese R, Politi R, and Peter G

Subjects
Diffusion, Gases analysis, Gases chemistry, Spectrum Analysis, Extraterrestrial Environment chemistry, Ice analysis, Meteoroids
Abstract

Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov-Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov-Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet's formation.

Published
2016
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18. Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years.

Author

Schulz R, Hilchenbach M, Langevin Y, Kissel J, Silen J, Briois C, Engrand C, Hornung K, Baklouti D, Bardyn A, Cottin H, Fischer H, Fray N, Godard M, Lehto H, Le Roy L, Merouane S, Orthous-Daunay FR, Paquette J, Rynö J, Siljeström S, Stenzel O, Thirkell L, Varmuza K, and Zaprudin B

Abstract

Comets are composed of dust and frozen gases. The ices are mixed with the refractory material either as an icy conglomerate, or as an aggregate of pre-solar grains (grains that existed prior to the formation of the Solar System), mantled by an ice layer. The presence of water-ice grains in periodic comets is now well established. Modelling of infrared spectra obtained about ten kilometres from the nucleus of comet Hartley 2 suggests that larger dust particles are being physically decoupled from fine-grained water-ice particles that may be aggregates, which supports the icy-conglomerate model. It is known that comets build up crusts of dust that are subsequently shed as they approach perihelion. Micrometre-sized interplanetary dust particles collected in the Earth's stratosphere and certain micrometeorites are assumed to be of cometary origin. Here we report that grains collected from the Jupiter-family comet 67P/Churyumov-Gerasimenko come from a dusty crust that quenches the material outflow activity at the comet surface. The larger grains (exceeding 50 micrometres across) are fluffy (with porosity over 50 per cent), and many shattered when collected on the target plate, suggesting that they are agglomerates of entities in the size range of interplanetary dust particles. Their surfaces are generally rich in sodium, which explains the high sodium abundance in cometary meteoroids. The particles collected to date therefore probably represent parent material of interplanetary dust particles. This argues against comet dust being composed of a silicate core mantled by organic refractory material and then by a mixture of water-dominated ices. At its previous recurrence (orbital period 6.5 years), the comet's dust production doubled when it was between 2.7 and 2.5 astronomical units from the Sun, indicating that this was when the nucleus shed its mantle. Once the mantle is shed, unprocessed material starts to supply the developing coma, radically changing its dust component, which then also contains icy grains, as detected during encounters with other comets closer to the Sun.

Published
2015
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19. Subsurface water and clay mineral formation during the early history of Mars.

Author

Ehlmann BL, Mustard JF, Murchie SL, Bibring JP, Meunier A, Fraeman AA, and Langevin Y

Subjects
Aluminum Silicates classification, Clay, Exobiology, Ice analysis, Silicates chemistry, Aluminum Silicates analysis, Aluminum Silicates chemistry, Extraterrestrial Environment chemistry, Groundwater analysis, Mars
Abstract

Clay minerals, recently discovered to be widespread in Mars's Noachian terrains, indicate long-duration interaction between water and rock over 3.7 billion years ago. Analysis of how they formed should indicate what environmental conditions prevailed on early Mars. If clays formed near the surface by weathering, as is common on Earth, their presence would indicate past surface conditions warmer and wetter than at present. However, available data instead indicate substantial Martian clay formation by hydrothermal groundwater circulation and a Noachian rock record dominated by evidence of subsurface waters. Cold, arid conditions with only transient surface water may have characterized Mars's surface for over 4 billion years, since the early-Noachian period, and the longest-duration aqueous, potentially habitable environments may have been in the subsurface.

Published
2011
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20. The surface composition and temperature of asteroid 21 Lutetia as observed by Rosetta/VIRTIS.

Author

Coradini A, Capaccioni F, Erard S, Arnold G, De Sanctis MC, Filacchione G, Tosi F, Barucci MA, Capria MT, Ammannito E, Grassi D, Piccioni G, Giuppi S, Bellucci G, Benkhoff J, Bibring JP, Blanco A, Blecka M, Bockelee-Morvan D, Carraro F, Carlson R, Carsenty U, Cerroni P, Colangeli L, Combes M, Combi M, Crovisier J, Drossart P, Encrenaz ET, Federico C, Fink U, Fonti S, Giacomini L, Ip WH, Jaumann R, Kuehrt E, Langevin Y, Magni G, McCord T, Mennella V, Mottola S, Neukum G, Orofino V, Palumbo P, Schade U, Schmitt B, Taylor F, Tiphene D, and Tozzi G

Abstract

The Visible, InfraRed, and Thermal Imaging Spectrometer (VIRTIS) on Rosetta obtained hyperspectral images, spectral reflectance maps, and temperature maps of the asteroid 21 Lutetia. No absorption features, of either silicates or hydrated minerals, have been detected across the observed area in the spectral range from 0.4 to 3.5 micrometers. The surface temperature reaches a maximum value of 245 kelvin and correlates well with topographic features. The thermal inertia is in the range from 20 to 30 joules meter(-2) kelvin(-1) second(-0.5), comparable to a lunarlike powdery regolith. Spectral signatures of surface alteration, resulting from space weathering, seem to be missing. Lutetia is likely a remnant of the primordial planetesimal population, unaltered by differentiation processes and composed of chondritic materials of enstatitic or carbonaceous origin, dominated by iron-poor minerals that have not suffered aqueous alteration.

Published
2011
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21. Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument.

Author

Mustard JF, Murchie SL, Pelkey SM, Ehlmann BL, Milliken RE, Grant JA, Bibring JP, Poulet F, Bishop J, Dobrea EN, Roach L, Seelos F, Arvidson RE, Wiseman S, Green R, Hash C, Humm D, Malaret E, McGovern JA, Seelos K, Clancy T, Clark R, Marais DD, Izenberg N, Knudson A, Langevin Y, Martin T, McGuire P, Morris R, Robinson M, Roush T, Smith M, Swayze G, Taylor H, Titus T, and Wolff M

Abstract

Phyllosilicates, a class of hydrous mineral first definitively identified on Mars by the OMEGA (Observatoire pour la Mineralogie, L'Eau, les Glaces et l'Activitié) instrument, preserve a record of the interaction of water with rocks on Mars. Global mapping showed that phyllosilicates are widespread but are apparently restricted to ancient terrains and a relatively narrow range of mineralogy (Fe/Mg and Al smectite clays). This was interpreted to indicate that phyllosilicate formation occurred during the Noachian (the earliest geological era of Mars), and that the conditions necessary for phyllosilicate formation (moderate to high pH and high water activity) were specific to surface environments during the earliest era of Mars's history. Here we report results from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of phyllosilicate-rich regions. We expand the diversity of phyllosilicate mineralogy with the identification of kaolinite, chlorite and illite or muscovite, and a new class of hydrated silicate (hydrated silica). We observe diverse Fe/Mg-OH phyllosilicates and find that smectites such as nontronite and saponite are the most common, but chlorites are also present in some locations. Stratigraphic relationships in the Nili Fossae region show olivine-rich materials overlying phyllosilicate-bearing units, indicating the cessation of aqueous alteration before emplacement of the olivine-bearing unit. Hundreds of detections of Fe/Mg phyllosilicate in rims, ejecta and central peaks of craters in the southern highland Noachian cratered terrain indicate excavation of altered crust from depth. We also find phyllosilicate in sedimentary deposits clearly laid by water. These results point to a rich diversity of Noachian environments conducive to habitability.

Published
2008
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22. A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express.

Author

Drossart P, Piccioni G, Gérard JC, Lopez-Valverde MA, Sanchez-Lavega A, Zasova L, Hueso R, Taylor FW, Bézard B, Adriani A, Angrilli F, Arnold G, Baines KH, Bellucci G, Benkhoff J, Bibring JP, Blanco A, Blecka MI, Carlson RW, Coradini A, Di Lellis A, Encrenaz T, Erard S, Fonti S, Formisano V, Fouchet T, Garcia R, Haus R, Helbert J, Ignatiev NI, Irwin P, Langevin Y, Lebonnois S, Luz D, Marinangeli L, Orofino V, Rodin AV, Roos-Serote MC, Saggin B, Stam DM, Titov D, Visconti G, Zambelli M, Tsang C, Ammannito E, Barbis A, Berlin R, Bettanini C, Boccaccini A, Bonnello G, Bouyé M, Capaccioni F, Cardesin A, Carraro F, Cherubini G, Cosi M, Dami M, De Nino M, Del Vento D, Di Giampietro M, Donati A, Dupuis O, Espinasse S, Fabbri A, Fave A, Veltroni IF, Filacchione G, Garceran K, Ghomchi Y, Giustizi M, Gondet B, Hello Y, Henry F, Hofer S, Huntzinger G, Kachlicki J, Knoll R, Kouach D, Mazzoni A, Melchiorri R, Mondello G, Monti F, Neumann C, Nuccilli F, Parisot J, Pasqui C, Perferi S, Peter G, Piacentino A, Pompei C, Réess JM, Rivet JP, Romano A, Russ N, Santoni M, Scarpelli A, Sémery A, Soufflot A, Stefanovitch D, Suetta E, Tarchi F, Tonetti N, Tosi F, and Ulmer B

Abstract

The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90-120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft and ground-based observations of infrared emission from CO2, O2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission owing to a lack of data and of an adequate observing geometry. Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 microm, extending from 90 to 120 km altitude, and of night-side O2 emission extending from 95 to 100 km. The CO2 emission peak occurs at approximately 115 km and varies with solar zenith angle over a range of approximately 10 km. This confirms previous modelling, and permits the beginning of a systematic study of the variability of the emission. The O2 peak emission happens at 96 km +/- 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted.

Published
2007
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23. South-polar features on Venus similar to those near the north pole.

Author

Piccioni G, Drossart P, Sanchez-Lavega A, Hueso R, Taylor FW, Wilson CF, Grassi D, Zasova L, Moriconi M, Adriani A, Lebonnois S, Coradini A, Bézard B, Angrilli F, Arnold G, Baines KH, Bellucci G, Benkhoff J, Bibring JP, Blanco A, Blecka MI, Carlson RW, Di Lellis A, Encrenaz T, Erard S, Fonti S, Formisano V, Fouchet T, Garcia R, Haus R, Helbert J, Ignatiev NI, Irwin PG, Langevin Y, Lopez-Valverde MA, Luz D, Marinangeli L, Orofino V, Rodin AV, Roos-Serote MC, Saggin B, Stam DM, Titov D, Visconti G, Zambelli M, Ammannito E, Barbis A, Berlin R, Bettanini C, Boccaccini A, Bonnello G, Bouye M, Capaccioni F, Moinelo AC, Carraro F, Cherubini G, Cosi M, Dami M, De Nino M, Del Vento D, Di Giampietro M, Donati A, Dupuis O, Espinasse S, Fabbri A, Fave A, Veltroni IF, Filacchione G, Garceran K, Ghomchi Y, Giustini M, Gondet B, Hello Y, Henry F, Hofer S, Huntzinger G, Kachlicki J, Knoll R, Driss K, Mazzoni A, Melchiorri R, Mondello G, Monti F, Neumann C, Nuccilli F, Parisot J, Pasqui C, Perferi S, Peter G, Piacentino A, Pompei C, Reess JM, Rivet JP, Romano A, Russ N, Santoni M, Scarpelli A, Semery A, Soufflot A, Stefanovitch D, Suetta E, Tarchi F, Tonetti N, Tosi F, and Ulmer B

Abstract

Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole. The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.

Published
2007
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24. Coupled ferric oxides and sulfates on the Martian surface.

Author

Bibring JP, Arvidson RE, Gendrin A, Gondet B, Langevin Y, Le Mouelic S, Mangold N, Morris RV, Mustard JF, Poulet F, Quantin C, and Sotin C

Subjects
Extraterrestrial Environment, Ferric Compounds, Mars, Water
Abstract

The Mars Exploration Rover (MER), Opportunity, showed that layered sulfate deposits in Meridiani Planum formed during a period of rising acidic ground water. Crystalline hematite spherules formed in the deposits as a consequence of aqueous alteration and were concentrated on the surface as a lag deposit as wind eroded the softer sulfate rocks. On the basis of Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) orbital data, we demonstrate that crystalline hematite deposits are associated with layered sulfates in other areas on Mars, implying that Meridiani-like ground water systems were indeed widespread and representative of an extensive acid sulfate aqueous system.

Published
2007
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25. Surface composition of Hyperion.

Author

Cruikshank DP, Dalton JB, Dalle Ore CM, Bauer J, Stephan K, Filacchione G, Hendrix AR, Hansen CJ, Coradini A, Cerroni P, Tosi F, Capaccioni F, Jaumann R, Buratti BJ, Clark RN, Brown RH, Nelson RM, McCord TB, Baines KH, Nicholson PD, Sotin C, Meyer AW, Bellucci G, Combes M, Bibring JP, Langevin Y, Sicardy B, Matson DL, Formisano V, Drossart P, and Mennella V

Abstract

Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25-26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high- and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus.

Published
2007
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26. No signature of clear CO2 ice from the 'cryptic' regions in Mars' south seasonal polar cap.

Author

Langevin Y, Douté S, Vincendon M, Poulet F, Bibring JP, Gondet B, Schmitt B, and Forget F

Abstract

The seasonal polar ice caps of Mars are composed mainly of CO2 ice. A region of low (< 30%) albedo has been observed within the south seasonal cap during early to mid-spring. The low temperature of this 'cryptic region' has been attributed to a clear slab of nearly pure CO2 ice, with the low albedo resulting from absorption by the underlying surface. Here we report near-infrared imaging spectroscopy of the south seasonal cap. The deep and broad CO2 absorption bands that are expected in the near-infrared with a thick transparent slab of CO2 ice are not observed. Models of the observed spectra indicate that the low albedo results from extensive dust contamination close to the surface of a CO2 ice layer, which could be linked to atmospheric circulation patterns. The strength of the CO2 absorption increases after mid-spring, so part of the dust is either carried away or buried more deeply in the ice layer during the CO2 ice sublimation process.

Published
2006
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27. Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data.

Author

Bibring JP, Langevin Y, Mustard JF, Poulet F, Arvidson R, Gendrin A, Gondet B, Mangold N, Pinet P, Forget F, Berthé M, Bibring JP, Gendrin A, Gomez C, Gondet B, Jouglet D, Poulet F, Soufflot A, Vincendon M, Combes M, Drossart P, Encrenaz T, Fouchet T, Merchiorri R, Belluci G, Altieri F, Formisano V, Capaccioni F, Cerroni P, Coradini A, Fonti S, Korablev O, Kottsov V, Ignatiev N, Moroz V, Titov D, Zasova L, Loiseau D, Mangold N, Pinet P, Douté S, Schmitt B, Sotin C, Hauber E, Hoffmann H, Jaumann R, Keller U, Arvidson R, Mustard JF, Duxbury T, Forget F, and Neukum G

Subjects
Aluminum Silicates, Atmosphere, Carbon Dioxide, Clay, Extraterrestrial Environment, Ferric Compounds, Silicates, Sulfates, Time, Mars, Minerals, Water
Abstract

Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.

Published
2006
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28. Composition and physical properties of Enceladus' surface.

Author

Brown RH, Clark RN, Buratti BJ, Cruikshank DP, Barnes JW, Mastrapa RM, Bauer J, Newman S, Momary T, Baines KH, Bellucci G, Capaccioni F, Cerroni P, Combes M, Coradini A, Drossart P, Formisano V, Jaumann R, Langevin Y, Matson DL, McCord TB, Nelson RM, Nicholson PD, Sicardy B, and Sotin C

Subjects
Ammonia analysis, Atmosphere, Carbon Dioxide analysis, Ice Cover, Spectrophotometry, Infrared, Extraterrestrial Environment chemistry, Ice analysis, Saturn
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, CO2, and amorphous and crystalline water ice, particularly in the region dubbed the "tiger stripes." An upper limit of 5 precipitable nanometers is derived for CO in the atmospheric column above Enceladus, and 2% for NH3 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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29. The evolution of Titan's mid-latitude clouds.

Author

Griffith CA, Penteado P, Baines K, Drossart P, Barnes J, Bellucci G, Bibring J, Brown R, Buratti B, Capaccioni F, Cerroni P, Clark R, Combes M, Coradini A, Cruikshank D, Formisano V, Jaumann R, Langevin Y, Matson D, McCord T, Mennella V, Nelson R, Nicholson P, Sicardy B, Sotin C, Soderblom LA, and Kursinski R

Subjects
Atmosphere, Extraterrestrial Environment, Spacecraft, Spectrum Analysis, Methane, Saturn
Abstract

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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30. A 5-micron-bright spot on Titan: evidence for surface diversity.

Author

Barnes JW, Brown RH, Turtle EP, McEwen AS, Lorenz RD, Janssen M, Schaller EL, Brown ME, Buratti BJ, Sotin C, Griffith C, Clark R, Perry J, Fussner S, Barbara J, West R, Elachi C, Bouchez AH, Roe HG, Baines KH, Bellucci G, Bibring JP, Capaccioni F, Cerroni P, Combes M, Coradini A, Cruikshank DP, Drossart P, Formisano V, Jaumann R, Langevin Y, Matson DL, McCord TB, Nicholson PD, and Sicardy B

Subjects
Atmosphere, Dry Ice, Extraterrestrial Environment, Ice, Methane, Spacecraft, Spectrum Analysis, Temperature, Water, Saturn
Abstract

Observations from the Cassini Visual and Infrared Mapping Spectrometer show an anomalously bright spot on Titan located at 80 degrees W and 20 degrees 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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31. Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan.

Author

Sotin C, Jaumann R, Buratti BJ, Brown RH, Clark RN, Soderblom LA, Baines KH, Bellucci G, Bibring JP, Capaccioni F, Cerroni P, Combes M, Coradini A, Cruikshank DP, Drossart P, Formisano V, Langevin Y, Matson DL, McCord TB, Nelson RM, Nicholson PD, Sicardy B, LeMouelic S, Rodriguez S, Stephan K, and Scholz CK

Subjects
Atmosphere chemistry, Gases chemistry, Geography, Hydrocarbons analysis, Hydrocarbons chemistry, Methane analysis, Methane chemistry, Spacecraft, Extraterrestrial Environment chemistry, Gases analysis, Ice analysis, Infrared Rays, Moon, Photography, Saturn
Abstract

Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar (ref. 1) and, similar to the Earth, N2 is the main component of the atmosphere. Methane is the second most important component, but it is photodissociated on a timescale of 10(7) years (ref. 3). This short timescale has led to the suggestion that Titan may possess a surface or subsurface reservoir of hydrocarbons to replenish the atmosphere. Here we report near-infrared images of Titan obtained on 26 October 2004 by the Cassini spacecraft. The images show that a widespread methane ocean does not exist; subtle albedo variations instead suggest topographical variations, as would be expected for a more solid (perhaps icy) surface. We also find a circular structure approximately 30 km in diameter that does not resemble any features seen on other icy satellites. We propose that the structure is a dome formed by upwelling icy plumes that release methane into Titan's atmosphere.

Published
2005
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32. Compositional maps of Saturn's moon Phoebe from imaging spectroscopy.

Author

Clark RN, Brown RH, Jaumann R, Cruikshank DP, Nelson RM, Buratti BJ, McCord TB, Lunine J, Baines KH, Bellucci G, Bibring JP, Capaccioni F, Cerroni P, Coradini A, Formisano V, Langevin Y, Matson DL, Mennella V, Nicholson PD, Sicardy B, Sotin C, Hoefen TM, Curchin JM, Hansen G, Hibbits K, and Matz KD

Abstract

The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within the sub-nebula in which Saturn itself formed. Here we report imaging spectroscopy of Phoebe resulting from the Cassini-Huygens spacecraft encounter on 11 June 2004. We mapped ferrous-iron-bearing minerals, bound water, trapped CO2, probable phyllosilicates, organics, nitriles and cyanide compounds. Detection of these compounds on Phoebe makes it one of the most compositionally diverse objects yet observed in our Solar System. It is likely that Phoebe's surface contains primitive materials from the outer Solar System, indicating a surface of cometary origin.

Published
2005
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33. Mars surface diversity as revealed by the OMEGA/Mars Express observations.

Author

Bibring JP, Langevin Y, Gendrin A, Gondet B, Poulet F, Berthé M, Soufflot A, Arvidson R, Mangold N, Mustard J, and Drossart P

Subjects
Carbon Dioxide, Dry Ice, Evolution, Planetary, Extraterrestrial Environment, Ferric Compounds, Geologic Sediments, Iron Compounds, Magnesium Compounds, Spacecraft, Water, Ice, Mars, Minerals, Silicates
Abstract

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) investigation, on board the European Space Agency Mars Express mission, is mapping the surface composition of Mars at a 0.3- to 5-kilometer resolution by means of visible-near-infrared hyperspectral reflectance imagery. The data acquired during the first 9 months of the mission already reveal a diverse and complex surface mineralogy, offering key insights into the evolution of Mars. OMEGA has identified and mapped mafic iron-bearing silicates of both the northern and southern crust, localized concentrations of hydrated phyllosilicates and sulfates but no carbonates, and ices and frosts with a water-ice composition of the north polar perennial cap, as for the south cap, covered by a thin carbon dioxide-ice veneer.

Published
2005
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34. Sulfates in Martian layered terrains: the OMEGA/Mars Express view.

Author

Gendrin A, Mangold N, Bibring JP, Langevin Y, Gondet B, Poulet F, Bonello G, Quantin C, Mustard J, Arvidson R, and LeMouélic S

Subjects
Calcium Sulfate, Extraterrestrial Environment, Geologic Sediments, Spacecraft, Temperature, Time, Mars, Minerals, Sulfates, Water
Abstract

The OMEGA/Mars Express hyperspectral imager identified hydrated sulfates on light-toned layered terrains on Mars. Outcrops in Valles Marineris, Margaritifer Sinus, and Terra Meridiani show evidence for kieserite, gypsum, and polyhydrated sulfates. This identification has its basis in vibrational absorptions between 1.3 and 2.5 micrometers. These minerals constitute direct records of the past aqueous activity on Mars.

Published
2005
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35. Olivine and pyroxene diversity in the crust of Mars.

Author

Mustard JF, Poulet F, Gendrin A, Bibring JP, Langevin Y, Gondet B, Mangold N, Bellucci G, and Altieri F

Subjects
Absorption, Atmosphere, Calcium, Extraterrestrial Environment, Geologic Sediments, Spacecraft, Spectroscopy, Near-Infrared, Spectrum Analysis, Time, Water, Iron Compounds, Magnesium Compounds, Mars, Minerals, Silicates
Abstract

Data from the Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) on the Mars Express spacecraft identify the distinct mafic, rock-forming minerals olivine, low-calcium pyroxene (LCP), and high-calcium pyroxene (HCP) on the surface of Mars. Olivine- and HCP-rich regions are found in deposits that span the age range of geologic units. However, LCP-rich regions are found only in the ancient Noachian-aged units, which suggests that melts for these deposits were derived from a mantle depleted in aluminum and calcium. Extended dark regions in the northern plains exhibit no evidence of strong mafic absorptions or absorptions due to hydrated materials.

Published
2005
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36. Spectral reflectance and morphologic correlations in eastern Terra Meridiani, Mars.

Author

Arvidson RE, Poulet F, Bibring JP, Wolff M, Gendrin A, Morris RV, Freeman JJ, Langevin Y, Mangold N, and Bellucci G

Subjects
Extraterrestrial Environment, Geologic Sediments, Spacecraft, Spectroscopy, Near-Infrared, Spectrum Analysis, Magnesium Sulfate, Mars, Minerals, Water
Abstract

The Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) hyperspectral image data covering eastern Terra Meridiani indicate the ubiquitous presence of molecular water in etched terrain materials that disconformably overlie heavily cratered terrains and underlie the hematite-bearing plains explored by the Opportunity rover. Identification of crystalline water in kieserite (MgSO4.H2O) is linked to materials exposed in a valley and plateau to the north of hematite-bearing plains. The mineralogical similarities between the etched terrain deposits examined with OMEGA data and the layered rocks examined by Opportunity imply that the ancient aqueous environments inferred from analyses of the rover data extend over regional scales.

Published
2005
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37. Sulfates in the north polar region of Mars detected by OMEGA/Mars Express.

Author

Langevin Y, Poulet F, Bibring JP, and Gondet B

Subjects
Atmosphere, Carbon Dioxide, Extraterrestrial Environment, Geologic Sediments, Minerals, Spacecraft, Spectroscopy, Near-Infrared, Spectrum Analysis, Temperature, Water, Calcium Sulfate, Mars, Sulfates
Abstract

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) imaging spectrometer observed the northern circumpolar regions of Mars at a resolution of a few kilometers. An extended region at 240 degrees E, 85 degrees N, with an area of 60 kilometers by 200 kilometers, exhibits absorptions at wavelengths of 1.45, 1.75, 1.94, 2.22, 2.26, and 2.48 micrometers. These signatures can be unambiguously attributed to calcium-rich sulfates, most likely gypsum. This region corresponds to the dark longitudinal dunes of Olympia Planitia. These observations reveal that water alteration played a major role in the formation of the constituting minerals of northern circumpolar terrains.

Published
2005
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38. Summer evolution of the north polar cap of Mars as observed by OMEGA/Mars Express.

Author

Langevin Y, Poulet F, Bibring JP, Schmitt B, Douté S, and Gondet B

Subjects
Carbon Dioxide, Extraterrestrial Environment, Seasons, Spacecraft, Spectroscopy, Near-Infrared, Spectrum Analysis, Water, Ice, Mars
Abstract

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) visible-infrared imaging spectrometer extensively observed regions of Mars with latitudes above 70 degrees N in late 2004 (heliocentric longitude from Ls 93 degrees to Ls 127 degrees ). The extent of water ice at the surface and the size of ice grains were monitored as a function of time. Bright, small-grained frost, which initially covered a large fraction of the polar cap, waned in favor of large-grained ice. In outlying regions, dominated by large-grained ice, the albedo increased over the period. Evaluating the dust content was model dependent. However, contamination of ice by dust was low.

Published
2005
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39. Perennial water ice identified in the south polar cap of Mars.

Author

Bibring JP, Langevin Y, Poulet F, Gendrin A, Gondet B, Berthé M, Soufflot A, Drossart P, Combes M, Bellucci G, Moroz V, Mangold N, and Schmitt B

Subjects
Carbon Dioxide analysis, Carbon Dioxide chemistry, Exobiology, Geography, Water chemistry, Extraterrestrial Environment chemistry, Ice analysis, Mars, Water analysis
Abstract

The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern cap was thought to be constituted of carbon dioxide ice. However, recent missions (NASA missions Mars Global Surveyor and Odyssey) have revealed surface structures, altimetry profiles, underlying buried hydrogen, and temperatures of the south polar regions that are thermodynamically consistent with a mixture of surface water ice and carbon dioxide. Here we present the first direct identification and mapping of both carbon dioxide and water ice in the martian high southern latitudes, at a resolution of 2 km, during the local summer, when the extent of the polar ice is at its minimum. We observe that this south polar cap contains perennial water ice in extended areas: as a small admixture to carbon dioxide in the bright regions; associated with dust, without carbon dioxide, at the edges of this bright cap; and, unexpectedly, in large areas tens of kilometres away from the bright cap.

Published
2004
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