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4. HiRISE observations of new impact craters exposing Martian ground ice

Author

Colin M. Dundas, M. R. Kennedy, Michael T. Mellon, Shane Byrne, Lee Saper, Alfred S. McEwen, and Ingrid Daubar

Subjects
geography, geography.geographical_feature_category, Ice stream, Lead (sea ice), Atmospheric sciences, Arctic ice pack, Astrobiology, Geophysics, Space and Planetary Science, Geochemistry and Petrology, Pancake ice, Earth and Planetary Sciences (miscellaneous), Sea ice, Cryosphere, Ice divide, Ice sheet, Geology
Abstract

Twenty small new impact craters or clusters have been observed to excavate bright material inferred to be ice at mid-latitudes and high latitudes on Mars. In the northern hemisphere, the craters are widely distributed geographically and occur at latitudes as low as 39°N. Stability modeling suggests that this ice distribution requires a long-term average atmospheric water vapor content around 25 precipitable micrometers, more than double the present value, which is consistent with the expected effect of recent orbital variations. Alternatively, near-surface humidity could be higher than expected for current column abundances if water vapor is not well mixed with atmospheric CO2, or the vapor pressure at the ice table could be lower due to salts. Ice in and around the craters remains visibly bright for months to years, indicating that it is clean ice rather than ice-cemented regolith. Although some clean ice may be produced by the impact process, it is likely that the original ground ice was excess ice (exceeding dry soil pore space) in many cases. Observations of the craters suggest small-scale heterogeneities in this excess ice. The origin of such ice is uncertain. Ice lens formation by migration of thin films of liquid is most consistent with local heterogeneity in ice content and common surface boulders, but in some cases, nearby thermokarst landforms suggest large amounts of excess ice that may be best explained by a degraded ice sheet.

Published
2014
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5. What the ancient phyllosilicates at Mawrth Vallis can tell us about possible habitability on early Mars

Author

Lee Saper, Scott L. Murchie, David J. Des Marais, Nancy K. McKeown, M. Darby Dyar, Damien Loizeau, Janice L. Bishop, and Mario Parente

Subjects
010504 meteorology & atmospheric sciences, Habitability, Outcrop, Noachian, Astronomy and Astrophysics, Mars Exploration Program, 01 natural sciences, law.invention, CRISM, Astrobiology, Orbiter, 13. Climate action, Space and Planetary Science, law, Abiogenesis, 0103 physical sciences, 010303 astronomy & astrophysics, Earth (classical element), 0105 earth and related environmental sciences
Abstract

Phyllosilicate deposits on Mars provide an opportunity to evaluate aqueous activity and the possibility that habitable environments may have existed during the Noachian period there. Analysis of hyperspectral visible/near-infrared (VNIR) Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) images has shown thick, complex profiles of phyllosilicates at Mawrth Vallis, Mars that are consistent with long-term aqueous activity and active chemistry. The ancient phyllosilicates in places such as this could have served as reaction centers for organic molecules. Previous experiments even suggest that phyllosilicates could have played a role in the origin of life. Regardless of whether life formed on early Mars or not, evaluating the type and thickness of clay-bearing units on Mars provides insights into plausible aqueous processes and chemical conditions both during the time of formation of the phyllosilicates, but also the subsequent period following their formation. The phyllosilicate outcrops at Mawrth Vallis extend across a broad (∼1000 km) region and exhibit a consistent general trend of Al-phyllosilicates and amorphous Al/Si species at the top of the clay profile and Fe/Mg-phyllosilicates on the bottom. This implies either a change in water chemistry, a change in material being altered, or an alteration profile where the upper clays were leached and altered more significantly than those below. A change in iron in the phyllosilicate units is also observed such that an Fe2+-bearing unit is frequently observed between the Fe3+- and Mg-rich phyllosilicates below and the Al/Si-rich materials above. Abrupt changes in chemistry like this are often indicative of biogeochemical activity on Earth. Possible microbe-clay interactions are considered in comparison with the CRISM observations. This study evaluates CRISM spectra from four images of different outcrops across the Mawrth Vallis region and evaluates the observed phyllosilicates and clay components in terms of plausible aqueous and microbial processes and the potential for retention of biosignatures, if present.

Published
2013
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6. Extensive linear ridge networks in Nili Fossae and Nilosyrtis, Mars: implications for fluid flow in the ancient crust

Author

Lee Saper and John F. Mustard

Subjects
Dike, geography, education.field_of_study, geography.geographical_feature_category, Population, Stratigraphic unit, Crust, Graben, Geophysics, Impact crater, Ridge, General Earth and Planetary Sciences, Shear zone, Petrology, education, Geomorphology, Geology
Abstract

[1] We have undertaken high-resolution mapping of the distribution, physical characteristics, orientation, and stratigraphic occurrence of >4000 linear ridge segments in two study areas, the Nilosyrtis highlands and the Nili Fossae region covering 1 × 105 km2. Ridges are typically hundreds of meters in length, meters in width, and up to tens of meters in height. Ridges form intersecting networks of anastomosing and bifurcating segments and consequently have variable orientations. Ridges are expressed in altered and brecciated basement materials on the floors and rims of impact craters deeply eroded by fluvial and other processes. The ridge-bearing basement is the lowest exposed stratigraphic unit and is overlain by a relatively unaltered mafic cap rock. Ridges are observed to terminate at the contact of these two units. We interpret the ridges to represent a complex of fractures, faults, shear zones, clastic and melt-bearing dikes, and pseudotachylytes that have been variably indurated by fluid percolation and mineralization. The fluid conduits were hardened relative to the host rock and are expressed as ridges due to differential erosion. The orientations of the exhumed ridges record the state of stress in the crust at the time of formation. In Nili Fossae, a significant population of ridges is aligned with the orientations of the Nili Fossae graben, indicating that their emplacement may be related to crustal loading of the Isidis Basin after the impact event. The association of ridges with the hydrated mineral-bearing basement suggests that, in the postimpact environment, the fractures served as conduits of preferential fluid flow, which were cemented by mineral precipitation.

Published
2013
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7. Formation of plagioclase-bearing peridotite and plagioclase-bearing wehrlite and gabbro suite through reactive crystallization: an experimental study

Author

Yan Liang and Lee Saper

Subjects
Peridotite, Basalt, Olivine, Gabbro, Geochemistry, Pyroxene, engineering.material, Poikilitic, Geophysics, Geochemistry and Petrology, Transition zone, engineering, Plagioclase, Geology
Abstract

Plagioclase-bearing peridotites are commonly associated with gabbroic rocks sampled around the Moho Transition Zone. Based on mineral chemistry, texture, and spatial relations, the formation of plagioclase-bearing peridotites has been attributed to impregnation of basalt into residual peridotites. We conducted reactive dissolution and crystallization experiments to test this hypothesis by reacting a primitive mid-ocean ridge basalt with a melt-impregnated lherzolite at 1,300 °C and 1 GPa and then cooling to 1,050 °C as pressure decreased to 0.7 GPa. Crystallization during cooling produced lithologic sequences of gabbro–wehrlite or gabbro–wehrlite–peridotite, depending on reaction time. Wehrlitic and peridotitic sections contain significant amounts of plagioclase interstitial to olivine and clinopyroxene and plagioclase compositions are spatially homogeneous. Clinopyroxene in the wehrlite–peridotite section is reprecipitated from the melt and exhibits poikilitic texture with small rounded olivine chadacrysts. Mineral composition in olivine and clinopyroxene varies spatially, both at the scale of the sample and within individual grains. Olivine grains that crystallized close to the melt–peridotite interface are enriched in iron due to their proximity to the basaltic melt reservoir. Consistent with many field studies, we observed gradual spatial variation in olivine and clinopyroxene composition across a lithologically sharp boundary between the gabbro and wehrlite–peridotite. Plagioclase compositions show no obvious dependence on distance from the melt–rock interface and were precipitated from late-stage trapped melts. Compositional trends of olivine, pyroxene, and plagioclase are consistent with previous experimental results and natural observations of the Moho Transition Zone. Different lithological sequences form based primarily on the melt–rock ratio, composition of the melt and host peridotite, and thermochemical conditions, but are expected to grade from gabbro to wehrlite or troctolite to peridotite. Plagioclase-bearing peridotite represents the low melt–rock ratio end member where pyroxene is only partially replaced by olivine and melt, whereas dunite is expected to form where melts overwhelm and consume all other phases. This study confirms that under nominally anhydrous conditions, the gabbro–wehrlite–plagioclase-peridotite sequence can be formed by reaction between basalt and lherzolite and subsequent crystallization at intermediate to low pressures. Melt–rock reaction is a fundamental process in the formation of new crust at the shallowest part of the melting column where pyroxene-undersaturated melts percolate through depleted peridotite.

Published
2014
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8. A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars

Author

J. P. Grotzinger, D. Y. Sumner, L. C. Kah, K. Stack, S. Gupta, L. Edgar, D. Rubin, K. Lewis, J. Schieber, N. Mangold, R. Milliken, P. G. Conrad, D. DesMarais, J. Farmer, K. Siebach, F. Calef, J. Hurowitz, S. M. McLennan, D. Ming, D. Vaniman, J. Crisp, A. Vasavada, K. S. Edgett, M. Malin, D. Blake, R. Gellert, P. Mahaffy, R. C. Wiens, S. Maurice, J. A. Grant, S. Wilson, R. C. Anderson, L. Beegle, R. Arvidson, B. Hallet, R. S. Sletten, M. Rice, J. Bell, J. Griffes, B. Ehlmann, R. B. Anderson, T. F. Bristow, W. E. Dietrich, G. Dromart, J. Eigenbrode, A. Fraeman, C. Hardgrove, K. Herkenhoff, L. Jandura, G. Kocurek, S. Lee, L. A. Leshin, R. Leveille, D. Limonadi, J. Maki, S. McCloskey, M. Meyer, M. Minitti, H. Newsom, D. Oehler, A. Okon, M. Palucis, T. Parker, S. Rowland, M. Schmidt, S. Squyres, A. Steele, E. Stolper, R. Summons, A. Treiman, R. Williams, A. Yingst, MSL Science Team, Osku Kemppinen, Nathan Bridges, Jeffrey R. Johnson, David Cremers, Austin Godber, Meenakshi Wadhwa, Danika Wellington, Ian McEwan, Claire Newman, Mark Richardson, Antoine Charpentier, Laurent Peret, Penelope King, Jennifer Blank, Gerald Weigle, Shuai Li, Kevin Robertson, Vivian Sun, Michael Baker, Christopher Edwards, Kenneth Farley, Hayden Miller, Megan Newcombe, Cedric Pilorget, Claude Brunet, Victoria Hipkin, Richard Léveillé, Geneviève Marchand, Pablo Sobrón Sánchez, Laurent Favot, George Cody, Lorenzo Flückiger, David Lees, Ara Nefian, Mildred Martin, Marc Gailhanou, Frances Westall, Guy Israël, Christophe Agard, Julien Baroukh, Christophe Donny, Alain Gaboriaud, Philippe Guillemot, Vivian Lafaille, Eric Lorigny, Alexis Paillet, René Pérez, Muriel Saccoccio, Charles Yana, Carlos Armiens-Aparicio, Javier Caride Rodríguez, Isaías Carrasco Blázquez, Felipe Gómez Gómez, Javier Gómez-Elvira, Sebastian Hettrich, Alain Lepinette Malvitte, Mercedes Marín Jiménez, Jesús Martínez-Frías, Javier Martín-Soler, F. Javier Martín-Torres, Antonio Molina Jurado, Luis Mora-Sotomayor, Guillermo Muñoz Caro, Sara Navarro López, Verónica Peinado-González, Jorge Pla-García, José Antonio Rodriguez Manfredi, Julio José Romeral-Planelló, Sara Alejandra Sans Fuentes, Eduardo Sebastian Martinez, Josefina Torres Redondo, Roser Urqui-O’Callaghan, María-Paz Zorzano Mier, Steve Chipera, Jean-Luc Lacour, Patrick Mauchien, Jean-Baptiste Sirven, Heidi Manning, Alberto Fairén, Alexander Hayes, Jonathan Joseph, Robert Sullivan, Peter Thomas, Audrey Dupont, Angela Lundberg, Noureddine Melikechi, Alissa Mezzacappa, Julia DeMarines, David Grinspoon, Günther Reitz, Benito Prats, Evgeny Atlaskin, Maria Genzer, Ari-Matti Harri, Harri Haukka, Henrik Kahanpää, Janne Kauhanen, Mark Paton, Jouni Polkko, Walter Schmidt, Tero Siili, Cécile Fabre, James Wray, Mary Beth Wilhelm, Franck Poitrasson, Kiran Patel, Stephen Gorevan, Stephen Indyk, Gale Paulsen, David Bish, Brigitte Gondet, Yves Langevin, Claude Geffroy, David Baratoux, Gilles Berger, Alain Cros, Claude d’Uston, Olivier Forni, Olivier Gasnault, Jérémie Lasue, Qiu-Mei Lee, Pierre-Yves Meslin, Etienne Pallier, Yann Parot, Patrick Pinet, Susanne Schröder, Mike Toplis, Éric Lewin, Will Brunner, Ezat Heydari, Cherie Achilles, Brad Sutter, Michel Cabane, David Coscia, Cyril Szopa, François Robert, Violaine Sautter, Stéphane Le Mouélic, Marion Nachon, Arnaud Buch, Fabien Stalport, Patrice Coll, Pascaline François, François Raulin, Samuel Teinturier, James Cameron, Sam Clegg, Agnès Cousin, Dorothea DeLapp, Robert Dingler, Ryan Steele Jackson, Stephen Johnstone, Nina Lanza, Cynthia Little, Tony Nelson, Richard B. Williams, Andrea Jones, Laurel Kirkland, Burt Baker, Bruce Cantor, Michael Caplinger, Scott Davis, Brian Duston, Donald Fay, David Harker, Paul Herrera, Elsa Jensen, Megan R. Kennedy, Gillian Krezoski, Daniel Krysak, Leslie Lipkaman, Elaina McCartney, Sean McNair, Brian Nixon, Liliya Posiolova, Michael Ravine, Andrew Salamon, Lee Saper, Kevin Stoiber, Kimberley Supulver, Jason Van Beek, Tessa Van Beek, Robert Zimdar, Katherine Louise French, Karl Iagnemma, Kristen Miller, Fred Goesmann, Walter Goetz, Stubbe Hviid, Micah Johnson, Matthew Lefavor, Eric Lyness, Elly Breves, M. Darby Dyar, Caleb Fassett, Laurence Edwards, Robert Haberle, Tori Hoehler, Jeff Hollingsworth, Melinda Kahre, Leslie Keely, Christopher McKay, Lora Bleacher, William Brinckerhoff, David Choi, Jason P. Dworkin, Melissa Floyd, Caroline Freissinet, James Garvin, Daniel Glavin, Daniel Harpold, David K. Martin, Amy McAdam, Alexander Pavlov, Eric Raaen, Michael D. Smith, Jennifer Stern, Florence Tan, Melissa Trainer, Arik Posner, Mary Voytek, Andrew Aubrey, Alberto Behar, Diana Blaney, David Brinza, Lance Christensen, Lauren DeFlores, Jason Feldman, Sabrina Feldman, Gregory Flesch, Insoo Jun, Didier Keymeulen, Michael Mischna, John Michael Morookian, Betina Pavri, Marcel Schoppers, Aaron Sengstacken, John J. Simmonds, Nicole Spanovich, Manuel de la Torre Juarez, Christopher R. Webster, Albert Yen, Paul Douglas Archer, Francis Cucinotta, John H. Jones, Richard V. Morris, Paul Niles, Elizabeth Rampe, Thomas Nolan, Martin Fisk, Leon Radziemski, Bruce Barraclough, Steve Bender, Daniel Berman, Eldar Noe Dobrea, Robert Tokar, Timothy Cleghorn, Wesley Huntress, Gérard Manhès, Judy Hudgins, Timothy Olson, Noel Stewart, Philippe Sarrazin, Edward Vicenzi, Mark Bullock, Bent Ehresmann, Victoria Hamilton, Donald Hassler, Joseph Peterson, Scot Rafkin, Cary Zeitlin, Fedor Fedosov, Dmitry Golovin, Natalya Karpushkina, Alexander Kozyrev, Maxim Litvak, Alexey Malakhov, Igor Mitrofanov, Maxim Mokrousov, Sergey Nikiforov, Vasily Prokhorov, Anton Sanin, Vladislav Tretyakov, Alexey Varenikov, Andrey Vostrukhin, Ruslan Kuzmin, Benton Clark, Michael Wolff, Oliver Botta, Darrell Drake, Keri Bean, Mark Lemmon, Susanne P. Schwenzer, Ella Mae Lee, Robert Sucharski, Miguel Ángel de Pablo Hernández, Juan José Blanco Ávalos, Miguel Ramos, Myung-Hee Kim, Charles Malespin, Ianik Plante, Jan-Peter Muller, Rafael Navarro-González, Ryan Ewing, William Boynton, Robert Downs, Mike Fitzgibbon, Karl Harshman, Shaunna Morrison, Onno Kortmann, Amy Williams, Günter Lugmair, Michael A. Wilson, Bruce Jakosky, Tonci Balic-Zunic, Jens Frydenvang, Jaqueline Kløvgaard Jensen, Kjartan Kinch, Asmus Koefoed, Morten Bo Madsen, Susan Louise Svane Stipp, Nick Boyd, John L. Campbell, Glynis Perrett, Irina Pradler, Scott VanBommel, Samantha Jacob, Tobias Owen, Hannu Savijärvi, Eckart Boehm, Stephan Böttcher, Sönke Burmeister, Jingnan Guo, Jan Köhler, César Martín García, Reinhold Mueller-Mellin, Robert Wimmer-Schweingruber, John C. Bridges, Timothy McConnochie, Mehdi Benna, Heather Franz, Hannah Bower, Anna Brunner, Hannah Blau, Thomas Boucher, Marco Carmosino, Sushil Atreya, Harvey Elliott, Douglas Halleaux, Nilton Rennó, Michael Wong, Robert Pepin, Beverley Elliott, John Spray, Lucy Thompson, Suzanne Gordon, Ann Ollila, Joshua Williams, Paulo Vasconcelos, Jennifer Bentz, Kenneth Nealson, Radu Popa, Jeffrey Moersch, Christopher Tate, Mackenzie Day, Raymond Francis, Emily McCullough, Ed Cloutis, Inge Loes ten Kate, Daniel Scholes, Susan Slavney, Thomas Stein, Jennifer Ward, Jeffrey Berger, John E. Moores, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, The University of Tennessee [Knoxville], Department of Earth Science and Technology [Imperial College London], Imperial College London, ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), US Geological Survey [Santa Cruz], United States Geological Survey [Reston] (USGS), Princeton University, Department of Geological Sciences [Bloomington], Indiana University [Bloomington], Indiana University System-Indiana University System, 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), Department of Geological Sciences [Providence], Brown University, NASA Goddard Space Flight Center (GSFC), NASA Ames Research Center (ARC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Geosciences [Stony Brook], Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), State University of New York (SUNY), NASA Johnson Space Center (JSC), NASA, Planetary Science Institute [Tucson] (PSI), Department of Physics [Guelph], University of Guelph, Space Remote Sensing Group (ISR-2), Los Alamos National Laboratory (LANL), 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), Center for Earth and Planetary Studies [Washington] (CEPS), Smithsonian National Air and Space Museum, Smithsonian Institution-Smithsonian Institution, Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Department of Geological Sciences [Austin], Jackson School of Geosciences (JSG), University of Texas at Austin [Austin]-University of Texas at Austin [Austin], Rensselaer Polytechnic Institute (RPI), Canadian Space Agency (CSA), NASA Headquarters, Institute of Meteoritics [Albuquerque] (IOM), The University of New Mexico [Albuquerque], University of Hawaii, Brock University [Canada], Cornell University [New York], Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], Massachusetts Institute of Technology (MIT), Lunar and Planetary Institute [Houston] (LPI), GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), University of 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), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), 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), Carnegie Institution for Science, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, and Petrology

Subjects
Geologic Sediments, Salinity, Extraterrestrial Environment, Nitrogen, General Science & Technology, Iron, Curiosity rover, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Astrobiology, MSL Science Team, Exobiology, MSL, Martian, Multidisciplinary, fluvial-lacustrine environments, Biosphere, Water, Phosphorus, Mars Exploration Program, 15. Life on land, Hydrogen-Ion Concentration, Carbon, Oxygen, Planetary science, Bays, 13. Climate action, Rocknest, Sample Analysis at Mars, Sedimentary rock, Oxidation-Reduction, Geology, Sulfur, Hydrogen
Abstract

International audience; The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, and phosphorus were measured directly as key biogenic elements; by inference, phosphorus is assumed to have been available. The environment probably had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars.

Published
2014
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9. Mars' surface radiation environment measured with the Mars science laboratory's curiosity rover

Author

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

Subjects
Extraterrestrial Environment, Surface Properties, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Cosmic ray, Radiation Dosage, Exploration of Mars, Astrobiology, Martian surface, Exobiology, galactic cosmic rays, solar energetic particles, Mars Science Laboratory’s Curiosity rover, Humans, Organic Chemicals, Particle radiation, Martian, Radiation Assessment Detector (RAD), Multidisciplinary, Mars Exploration Program, Space Flight, Radiation assessment detector, 13. Climate action, Health threat from cosmic rays, Deinococcus, Cosmic Radiation
Abstract

International audience; The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for similar to 300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

Published
2014
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10. Isotope ratios of H, C, and O in CO2 and H2O of the martian atmosphere

Author

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

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

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

Published
2013

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