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4. Early Mars sub-aerial environments conducive to prebiotic evolution

Author

William Rapin, Gilles Dromart, Benton Clark, Jürgen Schieber, Edwin Kite, Linda Kah, Lucy Thompson, Olivier Gasnault, Jérémie Lasue, Pierre-Yves Meslin, Patrick Gasda, and Nina Lanza

Abstract

Mars provides a unique record for early habitable environments 1–3 but its potential for an independent origin of life is uncertain 4,5. Prebiotic chemical evolution leading to incipient life requires specific environments and processes to occur 6. In particular, wet-dry cycling is known to strongly promote the self-assembly of organics, generating opportunistic mixtures and combinations of essential biopolymers 7–9. However, evidence for such process has been missing from the geological record of Mars explored so far. Here we report on new observations by the Curiosity rover at Gale crater indicating wet-dry cycling occurred on early Mars. We observed exhumed centimetric polygonal ridges, with distinct Y-junctions, which are characteristic of a fossilized cracking pattern that initially formed in fresh mud by the sustained action of wet-dry cycles. Given organics are present in the ancient sediments of Gale, our results suggest the evaporitic basin has been particularly conducive to prebiotic polymerization processes. The features are physically and temporally associated with the transition from clay to sulfate-bearing strata, a key mineral assemblage found elsewhere across Mars. It suggests that the Noachian-Hesperian transition (3.8 – 3.6 Gyrs ago) as a whole has been favorable to prebiotic evolution.

Published
2022
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5. AI-enabled dynamic finish machining optimization for sustained surface integrity

Author

David Adeniji, Julius Schoop, Hasan A. Poonawala, and Benton Clark

Subjects
0209 industrial biotechnology, Cutting tool, Computer science, Process (engineering), media_common.quotation_subject, 02 engineering and technology, Integrated approach, Advanced materials, 021001 nanoscience & nanotechnology, Industrial and Manufacturing Engineering, Reliability engineering, 020901 industrial engineering & automation, Machining, Mechanics of Materials, Quality (business), 0210 nano-technology, media_common, Surface integrity
Abstract

While machining processes are typically leveraged to establish geometric features, many functional characteristics of advanced materials are directly determined by their machining-induced quality, i.e. surface integrity. Current modeling approaches struggle to predict surface integrity, and typically neglect the effects of progressive tool-wear, resulting in inefficient ‘static’ process parameters. We present a novel integrated approach based on model-informed artificial intelligence (AI), which quickly and efficiently optimizes ‘dynamic’ process parameters. By maximizing the useful life of a cutting tool over which required quality parameters can be maintained, our paradigm will enable significantly more efficient processing of next-generation materials and components.

Published
2021
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6. Oxidized and Reduced Sulfur Observed by the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover Within the Glen Torridon Region at Gale Crater, Mars

Author

Gregory M. Wong, Heather B. Franz, Joanna V. Clark, Amy C. McAdam, James M. T. Lewis, Maëva Millan, Douglas W. Ming, Felipe Gomez, Benton Clark, Jennifer L. Eigenbrode, Rafael Navarro‐González, and Christopher H. House

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Published
2022
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7. The power of paired proximity science observations: Co-located data from SHERLOC and PIXL on Mars

Author

Joseph Razzell Hollis, Kelsey R. Moore, Sunanda Sharma, Luther Beegle, John P. Grotzinger, Abigail Allwood, William Abbey, Rohit Bhartia, Adrian J. Brown, Benton Clark, Edward Cloutis, Andrea Corpolongo, Jesper Henneke, Keyron Hickman-Lewis, Joel A. Hurowitz, Michael W.M. Jones, Yang Liu, Jesús Martinez-Frías, Ashley Murphy, David A.K. Pedersen, Svetlana Shkolyar, Sandra Siljeström, Andrew Steele, Mike Tice, Alan Treiman, Kyle Uckert, Scott VanBommel, and Anastasia Yanchilina

Subjects
Space and Planetary Science, Astronomy and Astrophysics
Abstract

We present a synthesis of PIXL elemental data and SHERLOC Raman spectra collected on two targets investigated by the Perseverance rover during the first year of its exploration of Jezero Crater, Mars. The Bellegarde target (in the Máaz formation) and Dourbes target (in the Séítah formation) exhibit distinctive mineralogies that are an ideal case study for in situ analysis by SHERLOC and PIXL. Each instrument alone produces valuable data about the chemistry and spatial distribution of mineral phases at the sub-millimeter scale. However, combining data from both instruments provides a more robust interpretation that overcomes the limitations of either instrument, for example: 1) Detection of correlated calcium and sulfur in Bellegarde by PIXL is corroborated by the co-located detection of calcium sulfate by SHERLOC. 2) Detection of sodium and chlorine in Dourbes is consistent with either chloride or oxychlorine salts, but SHERLOC does not detect perchlorate or chlorate. 3) A Raman peak at 1120 cm−1 in Dourbes could be sulfate or pyroxene, but elemental abundances from PIXL at that location are a better match to pyroxene. This study emphasizes the importance of analyzing co-located data from both instruments together, to obtain a more complete picture of sub-millimeter-scale mineralogy measured in situ in Jezero crater, Mars, by the Perseverance rover.

Published
2022
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8. Contributors

Author

Neyda M. Abreu, Conel M.O'D. Alexander, Victor Ali-Lagoa, José C. Aponte, Maria A. Barucci, Pierre Beck, Edward B. Bierhaus, Daniel T. Britt, Humberto Campins, Noel Chaumard, Beth E. Clark, Benton Clark, Edward A. Cloutis, Christopher Dreyer, Jason P. Dworkin, Linda T. Elkins-Tanton, Jamie E. Elsila, Joshua Emery, Marcello Fulchignoni, Leslie Gertsch, Daniel P. Glavin, Christine M. Hartzell, Amanda Hendrix, Charles Hibbitts, Kieren Howard, Matthew R.M. Izawa, Robert Jedicke, Natasha Johnson, Jerome B. Johnson, Anton V. Kulchitsky, Julia de León, Hal Levison, Javier Licandro, Stanley G. Love, Maggie McAdam, Timothy McCoy, Phil Metzger, Tatsuhiro Michikami, Takaaki Noguchi, Joseph A. Nuth, Craig E. Peterson, Carol Raymond, David M. Reeves, Andrew Rivkin, Alan Rubin, Paul Sanchez, Juan A. Sánchez, Daniel J. Scheeres, Joel C. Sercel, Driss Takir, Michael A. Velbel, Otis Walton, Hikaru Yabuta, Makoto Yoshikawa, Kris Zacny, Michael E. Zolensky, and Xiao-Duan Zou

Published
2018
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9. Mars Aqueous Chemistry Experiment (MACE)

Author

Benton, Clark C

Subjects
Lunar And Planetary Exploration
Abstract

The concept of an aqueous-based chemical analyzer for Martian surface materials has been demonstrated to be feasible. During the processes of analysis, design, breadboarding, and most importantly, testing, it has become quite apparent that there are many challenges in implementing such a system. Nonetheless, excellent progress has been made and a number of problems which arose have been solved. The ability to conduct this work under a development environment which is separate and which precedes the project-level development has allowed us to find solutions to these implementation realities at low cost. If the instrument had been selected for a mission without this laboratory pre-project work, the costs of implementation would be much higher. In the four areas covered in Sections D, E, F, and G of this Final Report, outstanding progress has been made. There still remains the task of flight-qualifying certain of the components. This is traditionally done under the aegis of a Flight Project, but just as the concept development can be done at much lower cost when kept small and focused, so could the qualification program of critical parts benefit. We recommend, therefore, that NASA consider means of such qualifications and brass-boarding, in advance of final flight development. This is a generic recommendation, but hardware such as the Mars aqueous chemistry experiment (MACE) and other similarly-new concepts are particularly applicable. MACE now has wide versatility, in being able to reliably dispense both liquids and solids as chemical reagents to an entire suite of samples. The hardware and the experiment is much simpler than was developed for the Viking Biology instrument, yet can accomplish all the inorganic chemical measurements that the Viking desing was capable of. In addition, it is much more flexible and versatile to new experiment protocols (and reagents) than the Viking design ever could have been. MACE opens up the opportunity for many different scientific disciplines to design sub- experiments and to benefit from the investigations that can be conducted. In this sense, it will have the value of a facility, although our recommendation would be that it be under the stewardship of a single lead investigator to insure that conflicting requirements not compromise the straight-forward design that have been achieved. MACE is an excellent candidate for upcoming Mars missions, including the Mars Surveyor Program (MSP) lander missions in 2001 and 2003. In addition, it could be used for any mission to the surface of any other planet or planetary body (including small bodies). An important next step is to encourage various investigators to propose specific uses for this experiment that specifically address their major scientific objectives for upcoming missions.

Published
1995

10. 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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11. 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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12. 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

13. The Suess-Urey mission (return of solar matter to Earth)

Author

Eileen K. Stansbery, Donald R. Sevilla, Donald Rapp, Firouz Naderi, Nicholas Smith, Marcia Neugebauer, Donald S. Burnett, Roger C. Wiens, David J. McComas, Donald Sweetnam, and Benton Clark

Subjects
Solar System, Extraterrestrial Environment, Astronomy, Aerospace Engineering, Astrobiology, Attitude control, Isotopes, Radiation Monitoring, Libration, Astrophysics::Solar and Stellar Astrophysics, Spacecraft, Physics, business.industry, Equipment Design, Containment of Biohazards, Space Flight, Elements, Solar wind, Research Design, Physics::Space Physics, Telecommunications, Astrophysics::Earth and Planetary Astrophysics, Antenna (radio), business, Spin (aerodynamics), Halo orbit
Abstract

The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.

Published
1996
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14. The ChemCam Instrument Suite on the Mars Science Laboratory (MSL) Rover: Body Unit and Combined System Tests

Author

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

Subjects
010401 analytical chemistry, 010502 geochemistry & geophysics, 01 natural sciences, 0104 chemical sciences, 0105 earth and related environmental sciences
Published
2012
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16. STARDUST: finessing expensive cometary sample returns

Author

Peter Tsou, Chen-wan Yen, J. M. Vellinga, Donald E. Brownlee, C. Benton Clark, Kenneth L. Atkins, and Stephen R. Price

Subjects
Engineering, Astronautics, Cosmic Dust, Concurrent engineering, Spacecraft, Extraterrestrial Environment, business.industry, Astronomy, Comet, Aerospace Engineering, Equipment Design, Meteoroids, Space Flight, Astrobiology, Project engineering, Research Design, Systems engineering, Project management, business, Cosmic dust, Total Quality Management
Abstract

The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.

Published
1996

18. Manned Mars mission - Perspectives and options

Author

Benton Clark

Subjects
Planetary surface, Spacecraft, Spacecraft propulsion, business.industry, Computer science, Artificial gravity, Cruise, Aerocapture, Leisure activity, Mars Exploration Program, Aerospace engineering, business
Abstract

Denver, CO, USA 80201 The astrodynamics of Mars mission launch opportunities set irreducible physical limits on transportation energetics, but many optional approaches are possible depending on flight times and use of Venus flyby gravity assists. Aerocapture and nuclear rocket propulsion technologies have large potential savings to the mission, but require careful strategies for implementation. Supporting human life while maintaining high performance under long-term isolation and the confining conditions of spaceborne and planetary surface environments will set important minimum limits on spacecraft size, configuration, mass, and power. Long-term missions will undoubtedly require serious engineering consideration of the special requirements for providing artificial gravity. Human performance and leisure activity planning will necessitate highly automated spacecraft operation during cruise modes. Autonomous performance will be particularly necessary during aerocapture maneuvers and planetary entry phases. Minimizing spacesuit weight for exploration in a Mars-gravity environment is a driving technology that previous missions in space and to the moon have not required. Earth-to-orbit transportation will require heavy lift launch vehicles as part of the Mars mission fleet.

Published
1990
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20. Satisfaction with work-life balance and the career and retirement plans of US oncologists.

Author

Shanafelt TD, Raymond M, Kosty M, Satele D, Horn L, Pippen J, Chu Q, Chew H, Clark WB, Hanley AE, Sloan J, and Gradishar WJ

Subjects
Adult, Career Choice, Family Characteristics, Female, Humans, Male, Middle Aged, Societies, Medical, Surveys and Questionnaires, United States, Job Satisfaction, Medical Oncology, Personal Satisfaction, Physicians psychology, Retirement
Abstract

Purpose: To evaluate satisfaction with work-life balance (WLB) and career plans of US oncologists., Methods: The American Society of Clinical Oncology conducted a survey of US oncologists evaluating satisfaction with WLB and career plans between October 2012 and March 2013. The sample included equal numbers of men and women from all career stages., Results: Of 2,998 oncologists contacted, 1,490 (49.7%) returned surveys. From 1,117 oncologists (37.3% of overall sample) completing full-length surveys, we evaluated satisfaction with WLB and career plans among the 1,058 who were not yet retired. The proportion of oncologists satisfied with WLB (n = 345; 33.4%) ranked lower than that reported for all other medical specialties in a recent national study. Regarding career plans, 270 oncologists (26.5%) reported a moderate or higher likelihood of reducing their clinical work hours in the next 12 months, 351 (34.3%) indicated a moderate or higher likelihood of leaving their current position within 24 months, and 273 (28.5%) planned to retire before 65 years of age. Multivariable analyses found women oncologists (odds ratio [OR], 0.458; P < .001) and those who devoted greater time to patient care (OR for each additional hour, 0.977; P < .001) were less likely to be satisfied with WLB. Satisfaction with WLB and burnout were the strongest predictors of intent to reduce clinical work hours and leave current position on multivariable analysis., Conclusion: Satisfaction with WLB among US oncologists seems lower than for other medical specialties. Dissatisfaction with WLB shows a strong relationship with plans to reduce hours and leave current practice. Given the pending US oncologist shortage, additional studies exploring interactions among WLB, burnout, and career satisfaction and their impact on career and retirement plans are warranted.

Published
2014
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