Author: "GSFC Solar System Exploration Division" / Publisher: hal ccsd - Searchworks@Jio Institute Digital Library Search Results

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24 results on '"GSFC Solar System Exploration Division"'

1. Abiotic input of fixed nitrogen by bolide impacts in CH4+CO2+N2 and H2+CH4+CO2+N2 atmospheres. Comparison with nitrate levels measured by the curiosity rover's sample analysis at mars instrument

Author: Navarro-González, Rafael, Navarro, Karina, Coll, Patrice, Mckay, Christopher, Sutter, Brad, Stern, Jennifer, Archer, P., Mcadam, Amy, Szopa, Cyril, Freissinet, Caroline, Franz, H., Buch, Arnaud, Prats, B., Millan, Maeva, Eigenbrode, L., Coscia, David, Teinturier, S., Bonnet, Jean-Yves, Glavin, D., Williams, A., Raulin, François, Cabane, Michel, Ming, D., Malespin, C., Mahaffy, Paul, Martín-Torres, F., Zorzano-Mier, Maria-Paz, Atreya, Sushil, Fraeman, A., Vasavada, Ashwin, Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), NASA Ames Research Center (ARC), Jacobs Technology ESCG, NASA Goddard Space Flight Center (GSFC), NASA Johnson Space Center (JSC), NASA, 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), Laboratoire de Génie des Procédés et Matériaux (LGPM), CentraleSupélec-Université Paris-Saclay, GSFC Solar System Exploration Division, 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), Telespazio France, Department of Computer science, Electrical and Space engineering, Luleå University of Technology (LUT), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), University of Michigan [Ann Arbor], University of Michigan System, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), and Cardon, Catherine
Subjects: [SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2021

2. Direct evidence for magnetic reconnection at the boundaries of magnetic switchbacks with Parker Solar Probe

Author: Vladimir Krasnoselskikh, Marco Velli, Robert J. MacDowall, Phyllis Whittlesey, Anthony W. Case, Davin Larson, T. Dudok de Wit, Keith Goetz, Marc Pulupa, Benoit Lavraud, Justin C. Kasper, David M. Malaspina, Vamsee Krishna Jagarlamudi, Kelly E. Korreck, N. Fargette, Clara Froment, Oleksiy Agapitov, A. Larosa, Stuart D. Bale, F. S. Mozer, C. Revillet, Michael L. Stevens, Matthieu Kretzschmar, 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), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire 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), University of Colorado [Boulder], Smithsonian Astrophysical Observatory, Smithsonian Institution, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), IACR Brooms Barn, Partenaires INRAE, University of California [Berkeley], University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), and 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)
Subjects: Field (physics), FOS: Physical sciences, Context (language use), Solar radius, Astrophysics, magnetic fields, 01 natural sciences, Current sheet, Physics - Space Physics, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Sun: heliosphere, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Magnetic reconnection, Space Physics (physics.space-ph), Magnetic field, Solar wind, Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, magnetic reconnection, Physics::Space Physics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Heliosphere
Abstract: Parker Solar Probe's first encounters with the Sun revealed the presence of ubiquitous localised magnetic deflections in the inner heliosphere; these structures, often called switchbacks, are particularly striking in solar wind streams originating from coronal holes. We report the direct evidence for magnetic reconnection occuring at the boundaries of three switchbacks crossed by Parker Solar Probe (PSP) at a distance of 45 to 48 solar radii of the Sun during its first encounter. We analyse the magnetic field and plasma parameters from the FIELDS and SWEAP instruments. The three structures analysed all show typical signatures of magnetic reconnection. The ion velocity and magnetic field are first correlated and then anti-correlated at the inbound and outbound edges of the bifurcated current sheets with a central ion flow jet. Most of the reconnection events have a strong guide field and moderate magnetic shear but one current sheet shows indications of quasi anti-parallel reconnection in conjunction with a magnetic field magnitude decrease by $90\%$. Given the wealth of intense current sheets observed by PSP, reconnection at switchbacks boundaries appears to be rare. However, as the switchback boundaries accomodate currents one can conjecture that the geometry of these boundaries offers favourable conditions for magnetic reconnection to occur. Such a mechanism would thus contribute in reconfiguring the magnetic field of the switchbacks, affecting the dynamics of the solar wind and eventually contributing to the blending of the structures with the regular wind as they propagate away from the Sun., Comment: 11 pages, 7 figures, 2 tables, accepted for publication in A&A, PSP special issue (v2: typos correction)
Published: 2021

3. Switchbacks: statistical properties and deviations from Alfvénicity

Author: T. Dudok de Wit, A. Larosa, Davin Larson, Michael L. Stevens, C. Revillet, Vladimir Krasnoselskikh, Marco Velli, Vamsee Krishna Jagarlamudi, Marc Pulupa, Kelly E. Korreck, A. W. Case, Robert J. MacDowall, Keith Goetz, Clara Froment, Justin C. Kasper, Stuart D. Bale, Peter Harvey, Oleksiy Agapitov, David M. Malaspina, 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), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, 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), Smithsonian Astrophysical Observatory, Smithsonian Institution, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), University of Colorado [Boulder], IACR Brooms Barn, and Partenaires INRAE
Subjects: 010504 meteorology & atmospheric sciences, Proton, Context (language use), Astrophysics, Classification of discontinuities, magnetic fields, Firehose instability, 01 natural sciences, magnetohydrodynamics (MHD), Physics - Space Physics, 0103 physical sciences, waves, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, Magnetic field, Computational physics, Shear (sheet metal), Solar wind, Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, Physics::Space Physics, Compressibility, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Context.Parker Solar Probe’s first solar encounter has revealed the presence of sudden magnetic field deflections in the slow Alfvénic solar wind. These structures, which are often called switchbacks, are associated with proton velocity enhancements.Aims.We study their statistical properties with a special focus on their boundaries.Methods.Using data from SWEAP and FIELDS, we investigate particle and wavefield properties. The magnetic boundaries are analyzed with the minimum variance technique.Results.Switchbacks are found to be Alfvénic in 73% of cases and compressible in 27%. The correlations between magnetic field magnitude and density fluctuations reveal the existence of both positive and negative correlations, and the absence of perturbations in the magnetic field magnitude. Switchbacks do not lead to a magnetic shear in the ambient field. Their boundaries can be interpreted in terms of rotational or tangential discontinuities. The former are more frequent.Conclusions.Our findings provide constraints on the possible generation mechanisms of switchbacks, which have to be able to also account for structures that are not purely Alfvénic. One of the possible candidates, among others, manifesting the described characteristics is the firehose instability.
Published: 2021

4. New evidence for climate and erosion history in Gale crater, Mars, from Curiosity’s ascent onto the Greenheugh pediment

Author: Bryk, Alexander B., Dietrich, William E., Lamb, Michael P., Grotzinger, John P., Ashwin Vasavada, Stack, Kathryn M., Ray Arvidson, Fedo, Christopher M., Valerie Fox, Kristen Bennett, Sanjeev Gupta, Wiens, Roger C., Williams, Rebecca M. E., Rachel Kronyak, Lewis, Kevin W., Rubin, David M., William Rapin, Laetitia Le Deit, Stéphane Le Mouélic, Edgett, Kenneth S., Abigail Fraeman, Steven Banham, Candice Bedford, Madison Hughes, Kah, Linda C., Eigendbrode, Jennifer L., Gwénaël Caravaca, Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Washington University in Saint Louis (WUSTL), Department of Earth and Planetary Sciences [Knoxville], The University of Tennessee [Knoxville], Department of Earth Sciences [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Arizona State University [Tempe] (ASU), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Los Alamos National Laboratory (LANL), Planetary Science Institute [Tucson] (PSI), Johns Hopkins University (JHU), University of California [Santa Cruz] (UCSC), University of California, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), 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), Malin Space Science Systems (MSSS), Lunar and Planetary Institute [Houston] (LPI), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), and American Geophysical Union
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Curiosity, [SDU]Sciences of the Universe [physics], Greenheugh pediment, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, MSL, Gale crater
Abstract: International audience; Curiosity’s southward traverse up the lower north slope of Mt. Sharp (in Gale crater, Mars) and across Glen Torridon has brought it in contact with the organics-bearing sediments of the Knockfarril Hill member, the light-toned, nodule-rich strata found at Western, Central, and Tower buttes, and to the abrupt truncation of these altered Murray sediments at the Greenheugh pediment. Curiosity ascended the steep northern edge of the Greenheugh pediment near Tower butte, thus accessing strata identified ~20 years ago as recording a major environmental transition in the history of Gale. The basal truncation surface of the pediment is the Siccar Point group (SPg) basal unconformity, which extends past Vera Rubin ridge (VRR) to the north. Above the unconformity lies a
Published: 2020

5. Constraining Ion-Scale Heating and Spectral Energy Transfer in Observations of Plasma Turbulence

Author: Phyllis Whittlesey, Stuart D. Bale, Roberto Livi, Benjamin D. G. Chandran, Thierry Dudok de Wit, Kelly E. Korreck, Trevor A. Bowen, Jasper Halekas, Anthony W. Case, Christopher H. K. Chen, Robert J. MacDowall, Michael L. Stevens, David M. Malaspina, Alfred Mallet, M. McManus, Peter R. Harvey, Justin C. Kasper, Keith Goetz, Marc Pulupa, John W. Bonnell, Die Duan, Alexandros Chasapis, Davin Larson, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Smithsonian Astrophysical Observatory, Smithsonian Institution, University of New Hampshire (UNH), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Queen Mary University of London (QMUL), 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)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), GSFC Solar System Exploration Division, and NASA Goddard Space Flight Center (GSFC)
Subjects: Physics, Range (particle radiation), Turbulence, General Physics and Astronomy, Spectral density, Energy flux, Kinetic energy, 7. Clean energy, 01 natural sciences, Ion, Computational physics, Nonlinear system, 13. Climate action, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Physics::Space Physics, 010306 general physics, Scaling
Abstract: International audience; We perform a statistical study of the turbulent power spectrum at inertial and kinetic scales observed during the first perihelion encounter of the Parker Solar Probe. We find that often there is an extremely steep scaling range of the power spectrum just above the ion-kinetic scales, similar to prior observations at 1 A.U., with a power-law index of around −4. Based on our measurements, we demonstrate that either a significant (>50%) fraction of the total turbulent energy flux is dissipated in this range of scales, or the characteristic nonlinear interaction time of the turbulence decreases dramatically from the expectation based solely on the dispersive nature of nonlinearly interacting kinetic Alfvén waves.
Published: 2020

6. The search for organic compounds with TMAH thermochemolysis: From Earth analyses to space exploration experiments

Author: Arnaud Buch, D. Coscia, Daniel P. Glavin, Michel Cabane, Caroline Freissinet, Melissa Guzman, Charles Malespin, Jennifer L. Eigenbrode, Maeva Millan, Cyril Szopa, Yuanyuan He, Samuel Teinturier, Amy J. Williams, Paul R. Mahaffy, Pin Lu, Laboratoire de Génie des Procédés et Matériaux (LGPM), CentraleSupélec-Université Paris-Saclay, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), University of Florida [Gainesville] (UF), Georgetown University [Washington] (GU), NASA Goddard Space Flight Center (GSFC), and GSFC Solar System Exploration Division
Subjects: Tetramethylammonium hydroxide, Internal standard, Tetramethylammonium hydroxide (TMAH), SAM and MOMA, 010401 analytical chemistry, Pyrolysis gc ms, Space experiment, 01 natural sciences, Derivatization, 0104 chemical sciences, Analytical Chemistry, Thermally assisted hydrolysis and methylation (THM), chemistry.chemical_compound, TMAH degradation, chemistry, Pyrolysis-GC/MS, [SDU]Sciences of the Universe [physics], In situ analysis, Environmental chemistry, Thermochemolysis, Quantitative analysis, Spectroscopy, Earth (classical element)
Abstract: International audience; Tetramethylammonium hydroxide (TMAH) is one of the most popular methylation reagents that have been increasingly used for the detection of organic compounds within a wide range of samples, such as soil, coal, lacquer, lignin, polymers and for in situ analysis of solid samples by space experiments. The analytical methods and instruments, experimental conditions, and the qualitative and quantitative analysis of organic compounds using TMAH thermochemolysis for the last 10 years were reviewed; additionally, the mechanism of TMAH thermochemolysis and TMAH degradation are overviewed herein. The objective of this paper is to give a broad view of the TMAH thermochemolysis analysis, to demonstrate how the technique can be used for the detection of organics on Mars and other planets, and to promote cooperation between different disciplines which may use thermochemolysis.
Published: 2020

7. New Frontiers-class Uranus Orbiter: A Case For Exploring The Feasibility of Achieving Multidisciplinary Science With a Mid-scale Mission

Author: Cohen, I, Beddingfield, C.B., Chancia, R.O., DiBraccio, G.A., Hedman, M., MacKenzie, S.M., Mauk, B. H., Sayanagi, K.M., Soderlund, K.M., Turtle, E.P., Adams, E.Y., Ahrens, C. J., Arridge, C.S., Brooks, S., Bunce, E., Charnoz, S., Clark, G.B., Coustenis, A, Dillman, R.A., Dutta, S., Fletcher, L.N., Harbison, R.A., Helled, Ravit, Holme, R., Jozwiak, L.M., Kasaba, Yasumasa, Kollmann, P., Luszcz-Cook, S., Mousis, O., Mura, A., Murakami, G., Parisi, M., Rymer, A. M., Stanley, S., Stephan, Katrin, Vervack, R.J., Wong, M.H., Wurz, P., Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), University of Idaho [Moscow, USA], Department of Physics [Moscow,USA], Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and 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)
Subjects: Planetengeologie, Uranus Mission, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2020

8. Benzoic Acid as the Preferred Precursor for the Chlorobenzene Detected on Mars: Insights from the Unique Cumberland Analog Investigation

Author: Paul R. Mahaffy, Richard V. Morris, Heather Graham, Charles Malespin, Jérémie Lasue, Erwin Dehouck, Cyril Szopa, Caroline Freissinet, C. A. Knudson, Amy McAdam, J. M. T. Lewis, Samuel Teinturier, 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), NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Washington], Howard University, Center for Research and Exploration in Space Science and Technology [GSFC] (CRESST), 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), GSFC Solar System Exploration Division, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), NASA Johnson Space Center (JSC), NASA, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Evolved gas analysis, Mars, Mass spectrometry, 01 natural sciences, Pre-biotic astrochemistry, chemistry.chemical_compound, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Planetary science, 010303 astronomy & astrophysics, Magnesium perchlorate, 0105 earth and related environmental sciences, Benzoic acid, Astronomy and Astrophysics, Mars Exploration Program, Astrobiology, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Chlorobenzene, [SDU]Sciences of the Universe [physics], Sample Analysis at Mars, Gas chromatography–mass spectrometry, Nuclear chemistry
Abstract: The Cumberland drill sample from the Sheepbed mudstone in Gale Crater, Mars, revealed the first evidence of an indigenous Martian organic molecule, chlorobenzene, with the Sample Analysis at Mars (SAM) instrument on Curiosity. We created in the laboratory a mineralogical analog of the Cumberland sample (CBA) to aid in the understanding of the precursor organic molecule(s) that led to the detection of chlorobenzene. The CBA was analyzed by visible/near-infrared spectrometry, and the results are in accordance with Mastcam multispectral and the Chemical Camera passive analyses of Cumberland on Mars, demonstrating that the CBA is a relevant analog. CBA aliquots were spiked with 0.5 wt. % of benzoic acid and 1–2 wt. % of magnesium perchlorate and were run in SAM Testbed (TB). The TB evolved gas analysis (EGA) showed similarities with the Cumberland EGA on Mars in terms of the major volatiles H2O, CO2, and O2. The TB gas chromatography mass spectrometry displayed the presence of chlorobenzene at 23–28 pmol and dichlorobenzene. CBA aliquots were also analyzed in the laboratory with SAM-like EGA and the results on the laboratory setup confirmed the generation of chlorobenzene by a reaction between the benzoic acid and the magnesium perchlorates. The case for benzoic acid as a potential precursor for the chlorobenzene detected in the Martian regolith is strengthened with this new supporting laboratory data from the CBA. The quantification of chlorobenzene in the TB led to prediction of organic precursor abundance on Mars of hundreds, if not thousands, of parts per millions by weight.
Published: 2020

9. Detecting Clouds in Mars Orbiter Laser Altimeter/Mars Global Surveyor Data with K-Means Methods

Author: Caillé, Vincent, Määttänen, Anni, Spiga, Aymeric, Falletti, Lola, Neumann, Gregory A., Cardon, Catherine, APPEL À PROJETS GÉNÉRIQUE 2018 - Modéliser des nuages exotiques de CO2 sur Mars - - MECCOM2018 - ANR-18-CE31-0013 - AAPG2018 - VALID, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), GSFC Solar System Exploration Division, and NASA Goddard Space Flight Center (GSFC)
Subjects: [SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics]
Abstract: International audience; The Mars Orbiter Laser Altimeter (MOLA) was an instrument aboard the Mars Global Surveyor spacecraft in charge of building a precise map of Mars’ topography using laser altimetry. However, sensitivity was better than expected, leading to the detection of features that could not be assigned to the surface. In particular, MOLA was the first instrument to detect polar winter CO2 ice clouds. Previous studies have attributed some laser returns to cloud signatures coming from the atmosphere. Due to the large amount of data to analyse, those studies required to very strict distinction criteria, but today there are efficient means for analysing huge datasets.K-means clustering methods seem to be good options to computionally analyse MOLA data. We proceed by applying the method on a single PEDR data file (about 10 % of data) as a test case. We first explore the observed parameters to find those that allow us to clearly separate surface and atmosphere (cloud) returns. We then use three independent optimisation methods, elbow, gap statistic and average silhouette, to determine the best number of clusters. We then apply the method to the whole data set, and eventually can plot spatial and temporal cloud distributions once the cloud cluster has been identified. Following the Neumann and al. paper (2003), we find that the product of surface reflectivity and two-way transmissivity of the atmosphere is the best parameter for distinguishing cloud and surface returns. Our three optimisation methods converge to an unique number of clusters for our test case. Plotting the clusters shows that one of them clearly identifies clouds returns, while other ones allow for identification of noise and surface returns. Our method allows us to find more clouds than previous studies due to less stringent detection criteria. Cloud distributions are in agreement with reference studies and tend to confirm the viability of our method. Next step is to work within the cloud cluster to separate different kinds of clouds (absorptive/reflective, CO2/water/dust...), possibly by using other unsupervised machine learning methods.
Published: 2020

10. Influence of the solar wind dynamic pressure on the ion precipitation: MAVEN observations and simulation results

Author: Ronan Modolo, Janet G. Luhmann, Bruce M. Jakosky, Antoine Martinez, Yaxue Dong, Francis G. Eparvier, Jasper Halekas, Takuya Hara, J. P. McFadden, Olivier Witasse, Shannon Curry, Robert Lillis, François Leblanc, Norberto Romanelli, Jean-Yves Chaufray, Ludivine Leclercq, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), HELIOS - LATMOS, 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), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], University of Virginia [Charlottesville], and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Sorbonne Université (SU)
Subjects: Materials science, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Energy flux, Flux, Magnetosphere, 01 natural sciences, 7. Clean energy, Ion, Computational physics, Atmosphere, Solar wind, Geophysics, 13. Climate action, Space and Planetary Science, Sputtering, [SDU]Sciences of the Universe [physics], Dynamic pressure, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience; We discuss the influence of the solar wind dynamic pressure on the ion precipitation using observations performed by MAVEN from the 04 June 2014 to the 20 July 2017. The increase of the dynamic pressure from 0.63 to 1.44nPa is clearly associated with an increase of the same order of magnitude of the precipitating oxygen ion energy flux measured by MAVEN/STATIC from 9.9 to 20.6 × 106eV. cm−2. sr−1. s−1at low energy (from 30 to 650 eV). In the same way, from 650 eV to 25000 eV, MAVEN/SWIA (all species) observed an increase from 22.4 to 42.8 × 107eV. cm−2. sr−1. s−1 of the precipitating ion energy flux.Performing two simulations using the average solar wind conditions for both solar dynamic pressure regimes observed by MAVEN as input of the LatHyS model (LATMOS Hybrid Simulation), we reproduce some of the key characteristics of the observed oxygen ion precipitation. We characterize the oxygen ions simulated by LatHyS by their energy and time of impact, their time of injection in the simulation and initial position and the mechanism by which these ions were created. The model suggests that the main cause of the increase of the heavy ion precipitation during an increase of the solar dynamic pressure is the increase of the ion production by charge exchange, proportional to the increase of the solar wind flux, which becomes the main contribution to the ion precipitation at high energy.
Published: 2020

11. First Detections of Dichlorobenzene Isomers and Trichloromethylpropane from Organic Matter Indigenous to Mars Mudstone in Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument Onboard the Curiosity Rover

Author: Michel Cabane, Heather B. Franz, Jennifer L. Eigenbrode, Paul R. Mahaffy, Cyril Szopa, Samuel Teinturier, R. Williams, Rafael Navarro-González, Maeva Millan, Melissa Guzman, Dawn Y. Sumner, Charles Malespin, Brad Sutter, Roger E. Summons, Arnaud Buch, Caroline Freissinet, Daniel P. Glavin, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Department of Biology [Washington], Georgetown University [Washington] (GU), Laboratoire de Génie des Procédés et Matériaux (LGPM), CentraleSupélec-Université Paris-Saclay, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Department of Earth and Planetary Sciences [Davis], University of California [Davis] (UC Davis), University of California-University of California, Jacobs Technology ESCG, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Center for Research and Exploration in Space Science and Technology [College Park] (CRESST), Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México (UNAM), and Universities Space Research Association (USRA)
Subjects: Geologic Sediments, 010504 meteorology & atmospheric sciences, Polycyclic aromatic hydrocarbon, Mars, Chlorobenzenes, 01 natural sciences, Chemical reaction, Gas Chromatography-Mass Spectrometry, Dichlorobenzene, chemistry.chemical_compound, Propane, 0103 physical sciences, Exobiology, Organic matter, Spacecraft, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, chemistry.chemical_classification, Total organic carbon, Stereoisomerism, Mars Exploration Program, 15. Life on land, Agricultural and Biological Sciences (miscellaneous), chemistry, 13. Climate action, Space and Planetary Science, Chlorobenzene, [SDU]Sciences of the Universe [physics], Environmental chemistry, Sample Analysis at Mars
Abstract: International audience; Chromatographic analysis of the Cumberland mudstone in Gale crater by the Sample Analysis at Mars (SAM) instrument revealed the detection of two to three isomers of dichlorobenzene. Their individual concentrations were estimated to be in the 0.5–17 ppbw range relatively to the sample mass. We also report the first detection of trichloromethylpropane, and the confirmation of the detection of chlorobenzene previously reported. Supporting laboratory experiments excluded the SAM internal background as the source of those compounds, thus confirming the organic carbon and chlorine of the newly detected chlorohydrocarbons are indigenous to the mudstone sample. Laboratory experiments also demonstrated that the chlorohydrocarbons were mainly produced from chemical reactions occurring in the SAM ovens between organic molecules and oxychlorines contained in the sample. The results we obtained show that meteoritic organics and tested chemical species (a polycyclic aromatic hydrocarbon, an amino acid, and a carboxylic acid) were plausible organic precursors of the chlorinated aromatic molecules detected with SAM, thus suggesting that they could be among the organic molecules present in the mudstone. Results from this study coupled with previously reported detections of chlorinated aromatics (
Published: 2020

12. The induced magnetosphere of Mars. Asymmetrical topology of the magnetic field lines

Author: Lev Zelenyi, John E. P. Connerney, Joachim Woch, Yong Wei, J. P. McFadden, Ronan Modolo, Markus Fraenz, Gina A. DiBraccio, Lihui Chai, Elena Grigorenko, Martin Paetzold, Eduard Dubinin, Jared Espley, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Rheinisches Institut für Umweltforschung (RIU), Universität zu Köln, CAS Key Laboratory of Earth and Planetary Physics (EPP), Institute of Geology and Geophysics [Beijing] (IGG), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), NASA Goddard Space Flight Center (GSFC), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, GSFC Solar System Exploration Division, Space Research Institute of the Russian Academy of Sciences (IKI), and Russian Academy of Sciences [Moscow] (RAS)
Subjects: Physics, 010504 meteorology & atmospheric sciences, Field line, Magnetosphere, Plasma, Mars Exploration Program, 010502 geochemistry & geophysics, 01 natural sciences, Magnetic field, Computational physics, Geophysics, [SDU]Sciences of the Universe [physics], Electric field, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Ionosphere, Interplanetary magnetic field, 0105 earth and related environmental sciences
Abstract: International audience; An asymmetrical pileup of the interplanetary magnetic field (IMF) leads to an additional draping of the field lines in the opposite direction to the motional electric field. Such a draping and the associated magnetic field forces push the ionosphere plasma in the transverse direction opening a passage for an ion trail which contains dense and slowly moving plasma. We found that wrapping of the field lines around Mars starts in the hemisphere pointing in the direction of the motional electric field and propagates to the opposite hemisphere where the cross‐flow component of the draped IMF changes sign in a broad area accompanied by the formation of loops of closed field lines. Reconnection near Mars accompanied by the generation of plasma vortices imposes serious constraints on the ion dynamics and their escape through the tail. The existence of all these features is confirmed by hybrid simulations.
Published: 2019

13. Recovery Timescales of the Dayside Martian Magnetosphere to IMF Variability

Author: Jared Espley, Ronan Modolo, François Leblanc, Gina A. DiBraccio, J. P. McFadden, Bruce M. Jakosky, J. R. Gruesbeck, Jasper Halekas, Norberto Romanelli, GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Center for Research and Exploration in Space Science and Technology [Baltimore] (CRESST), University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), and University of Colorado [Boulder]
Subjects: Martian, Physics, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Magnetosphere, Atmosphere of Mars, Astrophysics, Mars Exploration Program, 010502 geochemistry & geophysics, 01 natural sciences, Plume, Solar wind, Geophysics, Magnetosheath, 13. Climate action, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Interplanetary magnetic field, 0105 earth and related environmental sciences
Abstract: International audience; In this work we revisit an event observed by Mars Atmosphere and Volatile Evolution MissioN (MAVEN) in the solar wind where the Interplanetary Magnetic Field (IMF) rotates around the Mars‐Sun axis during approximately 6 minutes. Based on a time‐dependent LATMOS Hybrid Simulation, we determine recovery timescales of the dayside Martian magnetosphere normalized by the IMF variability timescale. Particularly, we find that such recovery timescales range between 8 s and 11 min for an ~90° IMF rotation that lasted 50 s (observed as part of the 6 minutes time interval), depending on the considered magnetospheric region. We also find that the O+ plume recovery timescales range between 40 s and 120 s, taking greater values for further downstream distances (at least up to 1 RM downstream from the terminator plane). This range is on the order of the magnetosheath O+ gyroperiod, showing the kinetic nature of the plume recovery process.
Published: 2019

14. Recovery Timescales of the Dayside Martian Magnetosphere to Interplanetary Magnetic Field Variability

Author: Romanelli, N., DiBraccio, Gina, Modolo, Ronan, Leblanc, François, Espley, Jared, Gruesbeck, Jacob, Connerney, Jack, Halekas, Jasper, Mcfadden, J., Jakosky, Bruce, GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), and University of Colorado [Boulder]
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract: International audience; Based on a time dependent LATMOS Hybrid Simulation run taking into account MAVEN observations, we have determined recovery timescales of the dayside martian magnetosphere and the O+ plume to observed Interplanetary Magnetic Field variability.
Published: 2019

15. Investigating the effects of gamma radiation on selected chemicals for use in biosignature detection instruments on the surface of Jupiter's moon Europa

Author: Cyril Szopa, Stephanie Getty, Daniel P. Glavin, Jason P. Dworkin, Arnaud Buch, Melissa Guzman, Andrej Grubisic, Xiang Li, Martin A. Carts, William B. Brinckerhoff, Jennifer C. Stern, Maeva Millan, Caroline Freissinet, Jennifer E. Eigenbrode, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Department of Biology [Washington], Georgetown University [Washington] (GU), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), and GSFC Radiation Effects Facility
Subjects: 010504 meteorology & atmospheric sciences, Perfluorotributylamine, 01 natural sciences, LD-MS, Ionizing radiation, Astrobiology, Jupiter, chemistry.chemical_compound, Desorption, 0103 physical sciences, Biosignature, 010303 astronomy & astrophysics, Chemical resistance, 0105 earth and related environmental sciences, Tetramethylammonium hydroxide, Radiation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, chemistry, 13. Climate action, Space and Planetary Science, Environmental science, Biosignatures, Gas chromatography–mass spectrometry, GC-MS, Europa, Wet chemistry
Abstract: International audience; Jupiter's moon Europa is a prime target for the search for potential signs of life in the solar system. The Europa Lander Science Definition Team Report outlined investigations and measurement requirements on a future Europa Lander and has led us to consider application of powerful techniques such as pyrolysis and derivatization gas chromatography mass spectrometry (GC-MS) and laser desorption mass spectrometry (LD-MS) to elucidate the organic composition of near-surface ice and minerals. Definitive identification of chemical biosignatures using such techniques is strongly enabled by the use of various chemicals, such as perfluorotributylamine (PFTBA) for the MS calibration, α-cyano-hydroxycinnamic acid (CHCA) for matrix-assisted laser desorption and ionization (MALDI) and N,N-dimethylformamide dimethyl acetal (DMF-DMA), N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA) and tetramethylammonium hydroxide (TMAH) for wet chemistry GC-MS protocols. The jovian radiation environment is known to represent a uniquely challenging risk to mission performance and lifetime, principally due to high radiation levels. To assess the potential ionizing radiation damage to these important chemicals, we tested their effectiveness following gamma radiation exposure doses up to the anticipated Europa Lander rating requirement of 300 krad(Si). The chemicals were sealed in glass ampules under vacuum (
Published: 2019

16. Recovery of Fatty Acids from Mineralogic Mars Analogs by TMAH Thermochemolysis for the Sample Analysis at Mars Wet Chemistry Experiment on the Curiosity Rover

Author: R. Williams, Rafael Navarro-González, Cyril Szopa, Paul R. Mahaffy, Amy J. Williams, Daniel P. Glavin, Jennifer L. Eigenbrode, Charles Malespin, Maeva Millan, Kathleen C. Benison, Roger E. Summons, Sarah Stewart Johnson, Arnaud Buch, Mary Beth Wilhelm, C. A. Knudson, Amy McAdam, J. M. T. Lewis, Kathleen L. Craft, Melissa Floyd, Shane S. O'Reilly, Caroline Freissinet, Slavka Andrejkovičová, Department of Physics, Astronomy, and Geosciences [Towson], Towson University [Towson, MD, United States], University of Maryland System-University of Maryland System, Center for Research and Exploration in Space Science and Technology [Baltimore] (CRESST), University of Maryland [Baltimore County] (UMBC), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), NASA Ames Research Center (ARC), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), UCD School od Earth Sciences, University College Dublin [Dublin] (UCD), Department of Biology [Washington], Georgetown University [Washington] (GU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Center for Research and Exploration in Space Science and Technology [College Park] (CRESST), University of Maryland [College Park], Universities Space Research Association (USRA), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Department of Geology and Geography [Morgantown], West Virginia University [Morgantown], Instituto de Ciencias Nucleares [Mexico], and Universidad Nacional Autónoma de México (UNAM)
Subjects: Time Factors, Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Iron, Carboxylic acid, Sample Analysis at Mars (SAM) instrument, Inorganic chemistry, Carboxylic Acids, Mars, Iron sulfide, Mass spectrometry, 01 natural sciences, Gas Chromatography-Mass Spectrometry, TMAH, chemistry.chemical_compound, Exobiology, 0103 physical sciences, MSL, Spacecraft, 010303 astronomy & astrophysics, Research Articles, 0105 earth and related environmental sciences, chemistry.chemical_classification, Minerals, Tetramethylammonium hydroxide, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Methanol, Fatty Acids, Temperature, Esters, Mars Exploration Program, Silicon Dioxide, Agricultural and Biological Sciences (miscellaneous), FAME, Quaternary Ammonium Compounds, Pyrolysis–gas chromatography–mass spectrometry, chemistry, 13. Climate action, Space and Planetary Science, Molecular biosignatures, Sample Analysis at Mars, Clay, Gas chromatography–mass spectrometry
Abstract: The Mars Curiosity rover carries a diverse instrument payload to characterize habitable environments in the sedimentary layers of Aeolis Mons. One of these instruments is Sample Analysis at Mars (SAM), which contains a mass spectrometer that is capable of detecting organic compounds via pyrolysis gas chromatography mass spectrometry (py-GC-MS). To identify polar organic molecules, the SAM instrument carries the thermochemolysis reagent tetramethylammonium hydroxide (TMAH) in methanol (hereafter referred to as TMAH). TMAH can liberate fatty acids bound in macromolecules or chemically bound monomers associated with mineral phases and make these organics detectable via gas chromatography mass spectrometry (GC-MS) by methylation. Fatty acids, a type of carboxylic acid that contains a carboxyl functional group, are of particular interest given their presence in both biotic and abiotic materials. This work represents the first analyses of a suite of Mars-analog samples using the TMAH experiment under select SAM-like conditions. Samples analyzed include iron oxyhydroxides and iron oxyhydroxysulfates, a mixture of iron oxides/oxyhydroxides and clays, iron sulfide, siliceous sinter, carbonates, and shale. The TMAH experiments produced detectable signals under SAM-like pyrolysis conditions when organics were present either at high concentrations or in geologically modern systems. Although only a few analog samples exhibited a high abundance and variety of fatty acid methyl esters (FAMEs), FAMEs were detected in the majority of analog samples tested. When utilized, the TMAH thermochemolysis experiment on SAM could be an opportunity to detect organic molecules bound in macromolecules on Mars. The detection of a FAME profile is of great astrobiological interest, as it could provide information regarding the source of martian organic material detected by SAM.
Published: 2019

17. Amino Acids in Antarctic Micrometeorites

Author: Parker, Eric, Engrand, Cecile, Dworkin, Jason P., Glavin, Daniel Patrick, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), GSFC Solar System Exploration Division, and NASA Goddard Space Flight Center (GSFC)
Subjects: [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2019

18. Systematic study of impact of Perchlorate on the derivatization reagents (TMAH and MTBSTFA) onboard SAM

Author: Buch, Arnaud, He, yuanyuan, Szopa, Cyril, Freissinet, Caroline, Millan, Maeva, Williams, A. J., Williams, R., Glavin, Daniel P., Guzman, Melissa, Eigenbrode, Jennifer L., Malespin, Charles, Bonnet, Jean-yves, Johnson, S. S., Teinturier, Samuel, Navarro-Gonzalez, R., Cabane, Michel, Mahaffy, Paul R., Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, 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), Department of Physics, Astronomy, and Geosciences [Towson], Towson University [Towson, MD, United States], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center (GSFC), GSFC Solar System Exploration Division, 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), Georgetown University [Washington] (GU), Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), 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), 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), and Universidad Nacional Autónoma de México (UNAM)
Subjects: [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; Sample Analysis at Mars (SAM) is an experiment of the Mars Science Laboratory mission and is mainly dedicated to the search for indigenous organic compounds in Gale crater on Mars. To reach its goals, SAM may operate by using pyrolysis-gas chromatography mass spectrometry (GC-MS) and pyrolysis-MS (EGA). In addition, SAM includes wet chemistry capabilities to support the extraction and analysis of polar organic compounds of high interest (e.g. amino acids) from solid samples. Wet chemistry experiments improve the detection of organic compounds both by enhancing the recovery of chemical species from the solid sample matrices, and by changing their chemical structure to make compounds more amenable to GC-MS. Two reactants are contained in SAM for wet chemistry: MTBSTFA/DMF (N-tert-Butyldimethylsilyl-N-methyltrifluoroacetamide/ Dimethylformamide) and TMAH (tetramethylammonium hydroxide) thermochemolysis. The procedures developed for running these wet chemistry experiments were originally optimized for chemical standards and analogues of martian soils. But as oxychlorine salts have since been detected in Gale crater, we have to take into account their presence and all the possible chemical reaction they could induce when in contact with organic material. Indeed, when they are heated, perchlorates and chlorates decompose into O2 and Cl2/HCl and those compounds can react (through oxidation, chlorination, etc.) with the indigenous organic matter. This is also the case for the derivatization reagents as well. For this reason, we systematically studied the possible interaction of derivatization agents with different perchlorates, and its influence on the analysis of organic molecules. With this aim, we have first listed all the organic compounds generated from the reactions of the different perchlorates (CaClO4, Mg(ClO4)2, Fe(ClO4)3) with the derivatization agents TMAH and MTBSTFA/DMF. The study has been carried out at several temperatures ranging from 200°C up to 900°C. Through these experiments, we are now able to identify the contribution of theses reactions to the organic background signal observed in SAM, and to follow it at the different temperatures the samples are exposed. Hence, we can propose optimal temperature parameters for near term SAM analyses with those derivatizing reagents.
Published: 2018

19. SAM and the organic matter in Gale Crater, Mars - Inventory and implications

Author: Freissinet, Caroline, Glavin, Daniel P., Szopa, Cyril, Buch, Arnaud, Eigenbrode, Jennifer L., Millan, Maeva, Sutter, Brad, Teinturier, Samuel, Malespin, Charles, Guzman, Melissa, Steele, A., Navarro-Gonzalez, R., Sumner, D. Y., Mahaffy, Paul R., PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, Jacobs Technology ESCG, Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], Laboratorio de Química de Plasmas y Estudios Planetarios [Mexico], Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México (UNAM)-Universidad Nacional Autónoma de México (UNAM), Department of Earth and Planetary Sciences [Davis], University of California [Davis] (UC Davis), University of California-University of California, 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), Carnegie Institution for Science, Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM)-Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Department of Earth and Planetary Sciences [Univ California Davis] (EPS - UC Davis), and University of California (UC)-University of California (UC)
Subjects: [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; The sample analysis at Mars (SAM) instrument onboard Curiosity rover is devoted to the search for organic molecules on Mars, which can provide important first clues of extinct or extant biota on the planet. We've identified molecules at various locations in Gale crater in the form of, 1) simple organic molecules released from pyrolyzed samples rich in clays and sulfates; chlorobenzene and dichloroalkanes were first identified in a mudstone, followed by the detection of at least two isomers of dichlorobenzene through a directed search. The pyrolysis of a drilled sample further down Curiosity's path led to the identification of S-bearing compounds such as thiophene and dimethylsulfide. The exact nature of the precursors and the origin of the low-temperature Cl-bearing and high temperature S-bearing molecules remain unclear. 2) More complex organic molecules with the use of derivatization. Two derivatization protocols were applied to SAM; a) an "opportunistic derivatization" that used the leak present in the system, and during which we can minimize interferences with perchlorates by removing O2/HCl before the reaction, and b) a full-cup derivatization, in which a cup containing the reagent was punctured. Both experiments led to complementary results, consistent with the presence of organic matter with a wider diversity than previously recognized. 3) High CO2 release at temperatures compatible with oxidation of organics, either from instrumental background or from the martian sample. However, the identification of any specific molecules remains difficult. Hundreds of parts per million of organics are estimated in the case that all of the CO2 comes from organic carbon decomposition. The detection of reduced organic compounds in martian near surface samples is a significant step towards understanding the presence, diversity and preservation of prebiotic or biotic molecular signatures on Mars. Lessons learned from the detection of organic molecules with SAM will feed forward to the planning of future experiments on this instrument and the next generation missions to Mars. It also enables a better understanding of the organics preservation potential of Mars samples in context, and therefore increases our ability to select future landing sites in the search for traces of life, and to wisely target samples to be returned.
Published: 2018

20. SPRITE (Saturn PRobe Interior and aTmosphere Explorer): A Saturn Entry Probe Mission Concept

Author: Atkinson, David H., Simon, Amy, Banfield, Don, Atreya, Sushil, Blacksberg, Jordana, Brinckerhoff, Will, Colaprete, Anthony, Coustenis, Athena, Fletcher, Leigh, Guillot, Tristan, Hofstadter, Mark, Lunine, Jonathan, Mahaffy, Paul, Marley, Mark, Mousis, Olivier, Spilker, Thomas, Trainer, Melissa, Webster, Chris, NASA Goddard Space Flight Center (GSFC), Cornell University [New York], University of Michigan [Ann Arbor], University of Michigan System, NASA Ames Research Center (ARC), 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), University of Leicester, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, GSFC Solar System Exploration Division, 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), and Université Nice Sophia Antipolis (1965 - 2019) (UNS)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: International audience; A Saturn entry probe mission concept is presented for in situ studies of the Saturn atmospheric composition, structure, and dynamics to a depth of 10 bars or greater.
Published: 2018

21. The Transiting Exoplanet Community Early Release Science Program for JWST

Author: Jacob L. Bean, Kevin B. Stevenson, Natalie M. Batalha, Zachory Berta-Thompson, Laura Kreidberg, Nicolas Crouzet, Björn Benneke, Michael R. Line, David K. Sing, Hannah R. Wakeford, Heather A. Knutson, Eliza M.-R. Kempton, Jean-Michel Désert, Ian Crossfield, Natasha E. Batalha, Julien de Wit, Vivien Parmentier, Joseph Harrington, Julianne I. Moses, Mercedes Lopez-Morales, Munazza K. Alam, Jasmina Blecic, Giovanni Bruno, Aarynn L. Carter, John W. Chapman, Leen Decin, Diana Dragomir, Thomas M. Evans, Jonathan J. Fortney, Jonathan D. Fraine, Peter Gao, Antonio García Muñoz, Neale P. Gibson, Jayesh M. Goyal, Kevin Heng, Renyu Hu, Sarah Kendrew, Brian M. Kilpatrick, Jessica Krick, Pierre-Olivier Lagage, Monika Lendl, Tom Louden, Nikku Madhusudhan, Avi M. Mandell, Megan Mansfield, Erin M. May, Giuseppe Morello, Caroline V. Morley, Nikolay Nikolov, Seth Redfield, Jessica E. Roberts, Everett Schlawin, Jessica J. Spake, Kamen O. Todorov, Angelos Tsiaras, Olivia Venot, William C. Waalkes, Peter J. Wheatley, Robert T. Zellem, Daniel Angerhausen, David Barrado, Ludmila Carone, Sarah L. Casewell, Patricio E. Cubillos, Mario Damiano, Miguel de Val-Borro, Benjamin Drummond, Billy Edwards, Michael Endl, Nestor Espinoza, Kevin France, John E. Gizis, Thomas P. Greene, Thomas K. Henning, Yucian Hong, James G. Ingalls, Nicolas Iro, Patrick G. J. Irwin, Tiffany Kataria, Fred Lahuis, Jérémy Leconte, Jorge Lillo-Box, Stefan Lines, Joshua D. Lothringer, Luigi Mancini, Franck Marchis, Nathan Mayne, Enric Palle, Emily Rauscher, Gaël Roudier, Evgenya L. Shkolnik, John Southworth, Mark R. Swain, Jake Taylor, Johanna Teske, Giovanna Tinetti, Pascal Tremblin, Gregory S. Tucker, Roy van Boekel, Ingo P. Waldmann, Ian C. Weaver, Tiziano Zingales, University of Chicago, Space Telescope Science Institute (STSci), NASA Ames Research Center (ARC), Department of Astrophysical and Planetary Sciences [Boulder], University of Colorado [Boulder], Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Instituto de Astrofisica de Canarias (IAC), Universidad de La Laguna [Tenerife - SP] (ULL), Département de Physique [Montréal], Université de Montréal [Montréal], School of Earth and Space Exploration [Tempe] (SESE), Arizona State University [Tempe] (ASU), University of Exeter, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Grinnell College, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology (MIT), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), University of Central Florida [Orlando], Space Science Institute [Boulder] (SSI), New York University [Abu Dhabi], NYU System (NYU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institute of Astronomy [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), University of California [Santa Cruz] (UCSC), University of California, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Zentrum für Astronomie und Astrophysik [Berlin] (ZAA), Technische Universität Berlin (TUB), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Center for Space and Habitability (CSH), University of Bern, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Brown University, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Austrian Academy of Sciences (OeAW), University of Warwick [Coventry], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), University of Michigan [Ann Arbor], University of Michigan System, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, The Foundation for Scientific and Industrial Research (SINTEF), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), Wesleyan University, Amsterdam University of Applied Sciences, Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Blue Marble Space Institute of Science (BMSIS), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Department of Physics and Astronomy [Leicester], University of Leicester, Space Research Institute of Austrian Academy of Sciences (IWF), INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Astrochemistry Laboratory [Greenbelt], Catholic University of America, McDonald Observatory, University of Texas at Austin [Austin], Center for Astrophysics and Space Astronomy [Boulder] (CASA), Department of Physics and Astronomy [Newark], University of Delaware [Newark], Cornell University, Infrared Processing and Analysis Center (IPAC), University of Vienna [Vienna], Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], SRON Netherlands Institute for Space Research (SRON), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Carl Sagan Center, SETI Institute, Department of Physics, University of Rome Tor Vergata, Maison de la Simulation (MDLS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Paris-Sud - Paris 11 (UP11)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Ames Laboratory [Ames, USA], Iowa State University (ISU)-U.S. Department of Energy (DOE), Low Energy Astrophysics (API, FNWI), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides ( CASSIOPEE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut d'Astrophysique de Paris ( IAP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Joseph Louis LAGRANGE ( LAGRANGE ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Plasmachemistry, CNR-IMIP, Katholieke Universiteit Leuven ( KU Leuven ), University of California [Santa Cruz] ( UCSC ), Eidgenössische Technische Hochschule, Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), Max-Planck-Institut für Astronomie ( MPIA ), Astrophysique Interactions Multi-échelles ( AIM - UMR 7158 - UMR E 9005 ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ), The Foundation for Scientific and Industrial Research ( SINTEF ), Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Astrophysical Sciences [Princeton], Princeton University, Center for Astrophysics and Space Astronomy [Boulder] ( CASA ), University of Colorado Boulder [Boulder], Dept of Physics, University of Florida [Gainesville], Stony Brook University [The State University of New York] ( SBU ), ECLIPSE 2018, Laboratoire d'Astrophysique de Bordeaux [Pessac] ( LAB ), Université de Bordeaux ( UB ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Bordeaux ( UB ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), University College of London [London] ( UCL ), Maison de la Simulation ( MDLS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Iowa State University ( ISU ) -U.S. Department of Energy ( DOE ), Université de Montréal (UdeM), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), University of Central Florida [Orlando] (UCF), University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), Technische Universität Berlin (TU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Stiftelsen for INdustriell og TEknisk Forskning Digital [Trondheim] (SINTEF Digital), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Cornell University [New York], Università degli Studi di Roma Tor Vergata [Roma], Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Smithsonian Institution-Harvard University [Cambridge], Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Harvard University-Smithsonian Institution, Technical University of Berlin / Technische Universität Berlin (TU), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Agence Spatiale Européenne = European Space Agency (ESA), and University of Oxford
Subjects: MODEL ATMOSPHERES, Exclusive access, 010504 meteorology & atmospheric sciences, Computer science, Science program, observational [methods], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, MIDINFRARED INSTRUMENT, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Planets and satellites: Individual, 01 natural sciences, EXTRASOLAR GIANT PLANETS, Planets and satellites: Atmospheres, individual (WASP-79b, WASP-43b, WASP-18b) [planets and satellites], Settore FIS/05 - Astronomia e Astrofisica, Methods: Observational, Planet, 0103 physical sciences, Early release, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, LIGHT CURVES, Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, Community engagement, TIME-SERIES PHOTOMETRY, THERMAL EMISSION, James Webb Space Telescope, Astrophysics::Instrumentation and Methods for Astrophysics, WEBB-SPACE-TELESCOPE, Astronomy and Astrophysics, HOT-JUPITER, atmospheres [planets and satellites], [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Data science, Methods observational, Exoplanet, 13. Climate action, Space and Planetary Science, Physical Sciences, HD 189733B, Astrophysics::Earth and Planetary Astrophysics, ATMOSPHERIC CIRCULATION, Astrophysics - Earth and Planetary Astrophysics
Abstract: The James Webb Space Telescope (JWST) presents the opportunity to transform our understanding of planets and the origins of life by revealing the atmospheric compositions, structures, and dynamics of transiting exoplanets in unprecedented detail. However, the high-precision, time-series observations required for such investigations have unique technical challenges, and prior experience with other facilities indicates that there will be a steep learning curve when JWST becomes operational. In this paper we describe the science objectives and detailed plans of the Transiting Exoplanet Community Early Release Science (ERS) Program, which is a recently approved program for JWST observations early in Cycle 1. The goal of this project, for which the obtained data will have no exclusive access period, is to accelerate the acquisition and diffusion of technical expertise for transiting exoplanet observations with JWST, while also providing a compelling set of representative datasets that will enable immediate scientific breakthroughs. The Transiting Exoplanet Community ERS Program will exercise the time-series modes of all four JWST instruments that have been identified as the consensus highest priorities, observe the full suite of transiting planet characterization geometries (transits, eclipses, and phase curves), and target planets with host stars that span an illustrative range of brightnesses. The observations in this program were defined through an inclusive and transparent process that had participation from JWST instrument experts and international leaders in transiting exoplanet studies. Community engagement in the project will be centered on a two-phase Data Challenge that culminates with the delivery of planetary spectra, time-series instrument performance reports, and open-source data analysis toolkits in time to inform the agenda for Cycle 2 of the JWST mission., Comment: PASP in press
Published: 2018

22. The Mars Atmosphere and Volatile Evolution (MAVEN) Mission

Author: Phillip C. Chamberlin, Nicholas M. Schneider, J. M. Grebowsky, Jean-Yves Chaufray, Jane L. Fox, Robert Lillis, D. D. Carson, W. P. Sidney, David Brain, C. Mazelle, C. L. Waters, C. Gomez-Rosa, O. Cheatom, Robert P. Lin, James P. McFadden, Bruce M. Jakosky, Gregory T. Delory, Janet G. Luhmann, Todd King, D. Toublanc, D. Baird, Paul R. Mahaffy, Xiaohua Fang, Mario H. Acuña, W. K. Peterson, G. Beutelschies, J. Morrissey, Russell A. Howard, William E. McClintock, D. W. Curtis, M. Jarosz, D. L. Mitchell, S. Cauffman, John Clarke, Martin B. Houghton, Robert H. Tolson, François Leblanc, David L. Mitchell, Jean-André Sauvaud, T. Priser, N. Jedrich, S. Demcak, Thomas E. Cravens, Anders Eriksson, M. Johnson, S. Habenicht, David Folta, Jasper Halekas, Wayne Kasprzak, Mehdi Benna, Frank Eparvier, A. I. F. Stewart, M. Kelley, Daniel N. Baker, Richard W. Zurek, Robert E. Ergun, Jared Espley, Stephen W. Bougher, Gregory M. Holsclaw, Franck Montmessin, S. Sparacino, A. DeWolfe, Franck Lefèvre, Mark R. Lankton, John E. P. Connerney, Thomas N. Woods, Davin Larson, Roger V. Yelle, L. Andersson, R. Bartlett, W. Possel, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, NASA Goddard Space Flight Center (GSFC), Lockheed Martin Corporation, NASA Johnson Space Center (JSC), NASA, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [Boston], Boston University [Boston] (BU), Department of Physics and Astronomy [Lawrence Kansas], University of Kansas [Lawrence] (KU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Swedish Institute of Space Physics [Uppsala] (IRF), Department of Physics [Dayton], Wright State University, University of Iowa [Iowa City], GSFC Solar System Exploration Division, PLANETO - LATMOS, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), National Institute of Aerospace [Hampton] (NIA), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], MAVEN, Mars, Exploration of Mars, 01 natural sciences, Astrobiology, law.invention, Atmosphere, Orbiter, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spacecraft, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Atmosphere of Mars, Mars Exploration Program, Aerobraking, Solar wind, Planetary science, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Solar-wind interactions
Abstract: International audience; The MAVEN spacecraft launched in November 2013, arrived at Mars in September 2014, and completed commissioning and began its one-Earth-year primary science mission in November 2014. The orbiter’s science objectives are to explore the interactions of the Sun and the solar wind with the Mars magnetosphere and upper atmosphere, to determine the structure of the upper atmosphere and ionosphere and the processes controlling it, to determine the escape rates from the upper atmosphere to space at the present epoch, and to measure properties that allow us to extrapolate these escape rates into the past to determine the total loss of atmospheric gas to space through time. These results will allow us to determine the importance of loss to space in changing the Mars climate and atmosphere through time, thereby providing important boundary conditions on the history of the habitability of Mars. The MAVEN spacecraft contains eight science instruments (with nine sensors) that measure the energy and particle input from the Sun into the Mars upper atmosphere, the response of the upper atmosphere to that input, and the resulting escape of gas to space. In addition, it contains an Electra relay that will allow it to relay commands and data between spacecraft on the surface and Earth.
Published: 2015

23. Global inventory and characterization of pyroclastic deposits on Mercury: New insights into pyroclastic activity from MESSENGER orbital data

Author: Brett W. Denevi, Zhiyong Xiao, Maria T. Zuber, Robert G. Strom, David E. Smith, Timothy A. Goudge, Deborah L. Domingue, Sean C. Solomon, James W. Head, David T. Blewett, William E. McClintock, Scott L. Murchie, Jeffrey J. Gillis-Davis, Gregory M. Holsclaw, Noam R. Izenberg, Laura Kerber, Joern Helbert, Gregory A. Neumann, Klaus Gwinner, Rachel L. Klima, Department of Geological Sciences [Providence], Brown University, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Planetary Science Institute [Tucson] (PSI), Hawaii Institute of Geophysics and Planetology (HIGP), University of Hawai‘i [Mānoa] (UHM), DLR Institute of Planetary Research, German Aerospace Center (DLR), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Department of Terrestrial Magnetism [Carnegie Institution], Carnegie Institution for Science [Washington], Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and Carnegie Institution for Science
Subjects: 010504 meteorology & atmospheric sciences, Lunar mare, Geochemistry, Pyroclastic rock, chemistry.chemical_element, Volcanism, 01 natural sciences, Space weathering, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Impact crater, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Pyroclastic Deposits, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, Mercury, Mercury (element), Geophysics, Planetary science, chemistry, 13. Climate action, Space and Planetary Science, Pyroclastic surge, Geology
Abstract: International audience; We present new observations of pyroclastic deposits on the surface of Mercury from data acquired during the orbital phase of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. The global analysis of pyroclastic deposits brings the total number of such identified features from 40 to 51. Some 90% of pyroclastic deposits are found within impact craters. The locations of most pyroclastic deposits appear to be unrelated to regional smooth plains deposits, except some deposits cluster around the margins of smooth plains, similar to the relation between many lunar pyroclastic deposits and lunar maria. A survey of the degradation state of the impact craters that host pyroclastic deposits suggests that pyroclastic activity occurred on Mercury over a prolonged interval. Measurements of surface reflectance by MESSENGER indicate that the pyroclastic deposits are spectrally distinct from their surrounding terrain, with higher reflectance values, redder (i.e., steeper) spectral slopes, and a downturn at wavelengths shorter than ~400 nm (i.e., in the near-ultraviolet region of the spectrum). Three possible causes for these distinctive characteristics include differences in transition metal content, physical properties (e.g., grain size), or degree of space weathering from average surface material on Mercury. The strength of the near-ultraviolet downturn varies among spectra of pyroclastic deposits and is correlated with reflectance at visible wavelengths. We suggest that this interdeposit variability in reflectance spectra is the result of either variable amounts of mixing of the pyroclastic deposits with underlying material or inherent differences in chemical and physical properties among pyroclastic deposits.
Published: 2014

24. Diurnal variations of Titan's ionosphere

Author: Cui, J., Galand, M., Yelle, R. V., Vuitton, Veronique, Wahlund, J.-E., Lavvas, Panayotis, Müller-Wodarg, I. C. F., Cravens, T. E., Kasprzak, W. T., Waite Jr., J. H., Space and Atmospheric Physics Group [London], Blackett Laboratory, Imperial College London-Imperial College London, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Department of Physics and Astronomy [Lawrence Kansas], University of Kansas [Lawrence] (KU), GSFC Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), the Science and Technology Facilities Council (STFC), NASA through grant NAG5-12699, subcontract 699083KC from the Southwest Research Institute, University Research Fellowship of the British Royal Society, and Jet Propulsion Laboratory contract 1283095
Subjects: [SDU]Sciences of the Universe [physics], ionosphere, Titan
Abstract: International audience; We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm−3 below ~1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.
Published: 2009

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24 results on '"GSFC Solar System Exploration Division"'

1. Abiotic input of fixed nitrogen by bolide impacts in CH4+CO2+N2 and H2+CH4+CO2+N2 atmospheres. Comparison with nitrate levels measured by the curiosity rover's sample analysis at mars instrument

2. Direct evidence for magnetic reconnection at the boundaries of magnetic switchbacks with Parker Solar Probe

3. Switchbacks: statistical properties and deviations from Alfvénicity

4. New evidence for climate and erosion history in Gale crater, Mars, from Curiosity’s ascent onto the Greenheugh pediment

5. Constraining Ion-Scale Heating and Spectral Energy Transfer in Observations of Plasma Turbulence

6. The search for organic compounds with TMAH thermochemolysis: From Earth analyses to space exploration experiments

7. New Frontiers-class Uranus Orbiter: A Case For Exploring The Feasibility of Achieving Multidisciplinary Science With a Mid-scale Mission

8. Benzoic Acid as the Preferred Precursor for the Chlorobenzene Detected on Mars: Insights from the Unique Cumberland Analog Investigation

9. Detecting Clouds in Mars Orbiter Laser Altimeter/Mars Global Surveyor Data with K-Means Methods

10. Influence of the solar wind dynamic pressure on the ion precipitation: MAVEN observations and simulation results

11. First Detections of Dichlorobenzene Isomers and Trichloromethylpropane from Organic Matter Indigenous to Mars Mudstone in Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument Onboard the Curiosity Rover

12. The induced magnetosphere of Mars. Asymmetrical topology of the magnetic field lines

13. Recovery Timescales of the Dayside Martian Magnetosphere to IMF Variability

14. Recovery Timescales of the Dayside Martian Magnetosphere to Interplanetary Magnetic Field Variability

15. Investigating the effects of gamma radiation on selected chemicals for use in biosignature detection instruments on the surface of Jupiter's moon Europa

16. Recovery of Fatty Acids from Mineralogic Mars Analogs by TMAH Thermochemolysis for the Sample Analysis at Mars Wet Chemistry Experiment on the Curiosity Rover

17. Amino Acids in Antarctic Micrometeorites

18. Systematic study of impact of Perchlorate on the derivatization reagents (TMAH and MTBSTFA) onboard SAM

19. SAM and the organic matter in Gale Crater, Mars - Inventory and implications

20. SPRITE (Saturn PRobe Interior and aTmosphere Explorer): A Saturn Entry Probe Mission Concept

21. The Transiting Exoplanet Community Early Release Science Program for JWST

22. The Mars Atmosphere and Volatile Evolution (MAVEN) Mission

23. Global inventory and characterization of pyroclastic deposits on Mercury: New insights into pyroclastic activity from MESSENGER orbital data

24. Diurnal variations of Titan's ionosphere

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24 results on '"GSFC Solar System Exploration Division"'

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