ALBERT

Description: Stable isotope ratios of H, C, and O are powerful indicators of a wide variety of planetary geophysical processes, and for Mars they reveal the record of loss of its atmosphere and subsequent interactions with its surface such as carbonate formation. We report in situ measurements of the isotopic ratios of D/H and (18)O/(16)O in water and (13)C/(12)C, (18)O/(16)O, (17)O/(16)O, and (13)C(18)O/(12)C(16)O in carbon dioxide, made in the martian atmosphere at Gale Crater from the Curiosity rover using the Sample Analysis at Mars (SAM)'s tunable laser spectrometer (TLS). Comparison between our measurements in the modern atmosphere and those of martian meteorites such as ALH 84001 implies that the martian reservoirs of CO2 and H2O were largely established ~4 billion years ago, but that atmospheric loss or surface interaction may be still ongoing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Webster, Chris R -- Mahaffy, Paul R -- Flesch, Gregory J -- Niles, Paul B -- Jones, John H -- Leshin, Laurie A -- Atreya, Sushil K -- Stern, Jennifer C -- Christensen, Lance E -- Owen, Tobias -- Franz, Heather -- Pepin, Robert O -- Steele, Andrew -- MSL Science Team -- Achilles, Cherie -- Agard, Christophe -- Alves Verdasca, Jose Alexandre -- Anderson, Robert -- Anderson, Ryan -- Archer, Doug -- Armiens-Aparicio, Carlos -- Arvidson, Ray -- Atlaskin, Evgeny -- Aubrey, Andrew -- Baker, Burt -- Baker, Michael -- Balic-Zunic, Tonci -- Baratoux, David -- Baroukh, Julien -- Barraclough, Bruce -- Bean, Keri -- Beegle, Luther -- Behar, Alberto -- Bell, James -- Bender, Steve -- Benna, Mehdi -- Bentz, Jennifer -- Berger, Gilles -- Berger, Jeff -- Berman, Daniel -- Bish, David -- Blake, David F -- Blanco Avalos, Juan J -- Blaney, Diana -- Blank, Jen -- Blau, Hannah -- Bleacher, Lora -- Boehm, Eckart -- Botta, Oliver -- Bottcher, Stephan -- Boucher, Thomas -- Bower, Hannah -- Boyd, Nick -- Boynton, Bill -- Breves, Elly -- Bridges, John -- Bridges, Nathan -- Brinckerhoff, William -- Brinza, David -- Bristow, Thomas -- Brunet, Claude -- Brunner, Anna -- Brunner, Will -- Buch, Arnaud -- Bullock, Mark -- Burmeister, Sonke -- Cabane, Michel -- Calef, Fred -- Cameron, James -- Campbell, John -- Cantor, Bruce -- Caplinger, Michael -- Caride Rodriguez, Javier -- Carmosino, Marco -- Carrasco Blazquez, Isaias -- Charpentier, Antoine -- Chipera, Steve -- Choi, David -- Clark, Benton -- Clegg, Sam -- Cleghorn, Timothy -- Cloutis, Ed -- Cody, George -- Coll, Patrice -- Conrad, Pamela -- Coscia, David -- Cousin, Agnes -- Cremers, David -- Crisp, Joy -- Cros, Alain -- Cucinotta, Frank -- d'Uston, Claude -- Davis, Scott -- Day, Mackenzie -- de la Torre Juarez, Manuel -- DeFlores, Lauren -- DeLapp, Dorothea -- DeMarines, Julia -- DesMarais, David -- Dietrich, William -- Dingler, Robert -- Donny, Christophe -- Downs, Bob -- Drake, Darrell -- Dromart, Gilles -- Dupont, Audrey -- Duston, Brian -- Dworkin, Jason -- Dyar, M Darby -- Edgar, Lauren -- Edgett, Kenneth -- Edwards, Christopher -- Edwards, Laurence -- Ehlmann, Bethany -- Ehresmann, Bent -- Eigenbrode, Jen -- Elliott, Beverley -- Elliott, Harvey -- Ewing, Ryan -- Fabre, Cecile -- Fairen, Alberto -- Farley, Ken -- Farmer, Jack -- Fassett, Caleb -- Favot, Laurent -- Fay, Donald -- Fedosov, Fedor -- Feldman, Jason -- Feldman, Sabrina -- Fisk, Marty -- Fitzgibbon, Mike -- Floyd, Melissa -- Fluckiger, Lorenzo -- Forni, Olivier -- Fraeman, Abby -- Francis, Raymond -- Francois, Pascaline -- Freissinet, Caroline -- French, Katherine Louise -- Frydenvang, Jens -- Gaboriaud, Alain -- Gailhanou, Marc -- Garvin, James -- Gasnault, Olivier -- Geffroy, Claude -- Gellert, Ralf -- Genzer, Maria -- Glavin, Daniel -- Godber, Austin -- Goesmann, Fred -- Goetz, Walter -- Golovin, Dmitry -- Gomez Gomez, Felipe -- Gomez-Elvira, Javier -- Gondet, Brigitte -- Gordon, Suzanne -- Gorevan, Stephen -- Grant, John -- Griffes, Jennifer -- Grinspoon, David -- Grotzinger, John -- Guillemot, Philippe -- Guo, Jingnan -- Gupta, Sanjeev -- Guzewich, Scott -- Haberle, Robert -- Halleaux, Douglas -- Hallet, Bernard -- Hamilton, Vicky -- Hardgrove, Craig -- Harker, David -- Harpold, Daniel -- Harri, Ari-Matti -- Harshman, Karl -- Hassler, Donald -- Haukka, Harri -- Hayes, Alex -- Herkenhoff, Ken -- Herrera, Paul -- Hettrich, Sebastian -- Heydari, Ezat -- Hipkin, Victoria -- Hoehler, Tori -- Hollingsworth, Jeff -- Hudgins, Judy -- Huntress, Wesley -- Hurowitz, Joel -- Hviid, Stubbe -- Iagnemma, Karl -- Indyk, Steve -- Israel, Guy -- Jackson, Ryan -- Jacob, Samantha -- Jakosky, Bruce -- Jensen, Elsa -- Jensen, Jaqueline Klovgaard -- Johnson, Jeffrey -- Johnson, Micah -- Johnstone, Steve -- Jones, Andrea -- Joseph, Jonathan -- Jun, Insoo -- Kah, Linda -- Kahanpaa, Henrik -- Kahre, Melinda -- Karpushkina, Natalya -- Kasprzak, Wayne -- Kauhanen, Janne -- Keely, Leslie -- Kemppinen, Osku -- Keymeulen, Didier -- Kim, Myung-Hee -- Kinch, Kjartan -- King, Penny -- Kirkland, Laurel -- Kocurek, Gary -- Koefoed, Asmus -- Kohler, Jan -- Kortmann, Onno -- Kozyrev, Alexander -- Krezoski, Jill -- Krysak, Daniel -- Kuzmin, Ruslan -- Lacour, Jean Luc -- Lafaille, Vivian -- Langevin, Yves -- Lanza, Nina -- Lasue, Jeremie -- Le Mouelic, Stephane -- Lee, Ella Mae -- Lee, Qiu-Mei -- Lees, David -- Lefavor, Matthew -- Lemmon, Mark -- Lepinette Malvitte, Alain -- Leveille, Richard -- Lewin-Carpintier, Eric -- Lewis, Kevin -- Li, Shuai -- Lipkaman, Leslie -- Little, Cynthia -- Litvak, Maxim -- Lorigny, Eric -- Lugmair, Guenter -- Lundberg, Angela -- Lyness, Eric -- Madsen, Morten -- Maki, Justin -- Malakhov, Alexey -- Malespin, Charles -- Malin, Michael -- Mangold, Nicolas -- Manhes, Gerard -- Manning, Heidi -- Marchand, Genevieve -- Marin Jimenez, Mercedes -- Martin Garcia, Cesar -- Martin, Dave -- Martin, Mildred -- Martinez-Frias, Jesus -- Martin-Soler, Javier -- Martin-Torres, F Javier -- Mauchien, Patrick -- Maurice, Sylvestre -- McAdam, Amy -- McCartney, Elaina -- McConnochie, Timothy -- McCullough, Emily -- McEwan, Ian -- McKay, Christopher -- McLennan, Scott -- McNair, Sean -- Melikechi, Noureddine -- Meslin, Pierre-Yves -- Meyer, Michael -- Mezzacappa, Alissa -- Miller, Hayden -- Miller, Kristen -- Milliken, Ralph -- Ming, Douglas -- Minitti, Michelle -- Mischna, Michael -- Mitrofanov, Igor -- Moersch, Jeff -- Mokrousov, Maxim -- Molina Jurado, Antonio -- Moores, John -- Mora-Sotomayor, Luis -- Morookian, John Michael -- Morris, Richard -- Morrison, Shaunna -- Mueller-Mellin, Reinhold -- Muller, Jan-Peter -- Munoz Caro, Guillermo -- Nachon, Marion -- Navarro Lopez, Sara -- Navarro-Gonzalez, Rafael -- Nealson, Kenneth -- Nefian, Ara -- Nelson, Tony -- Newcombe, Megan -- Newman, Claire -- Newsom, Horton -- Nikiforov, Sergey -- Nixon, Brian -- Noe Dobrea, Eldar -- Nolan, Thomas -- Oehler, Dorothy -- Ollila, Ann -- Olson, Timothy -- de Pablo Hernandez, Miguel Angel -- Paillet, Alexis -- Pallier, Etienne -- Palucis, Marisa -- Parker, Timothy -- Parot, Yann -- Patel, Kiran -- Paton, Mark -- Paulsen, Gale -- Pavlov, Alex -- Pavri, Betina -- Peinado-Gonzalez, Veronica -- Peret, Laurent -- Perez, Rene -- Perrett, Glynis -- Peterson, Joe -- Pilorget, Cedric -- Pinet, Patrick -- Pla-Garcia, Jorge -- Plante, Ianik -- Poitrasson, Franck -- Polkko, Jouni -- Popa, Radu -- Posiolova, Liliya -- Posner, Arik -- Pradler, Irina -- Prats, Benito -- Prokhorov, Vasily -- Purdy, Sharon Wilson -- Raaen, Eric -- Radziemski, Leon -- Rafkin, Scot -- Ramos, Miguel -- Rampe, Elizabeth -- Raulin, Francois -- Ravine, Michael -- Reitz, Gunther -- Renno, Nilton -- Rice, Melissa -- Richardson, Mark -- Robert, Francois -- Robertson, Kevin -- Rodriguez Manfredi, Jose Antonio -- Romeral-Planello, Julio J -- Rowland, Scott -- Rubin, David -- Saccoccio, Muriel -- Salamon, Andrew -- Sandoval, Jennifer -- Sanin, Anton -- Sans Fuentes, Sara Alejandra -- Saper, Lee -- Sarrazin, Philippe -- Sautter, Violaine -- Savijarvi, Hannu -- Schieber, Juergen -- Schmidt, Mariek -- Schmidt, Walter -- Scholes, Daniel -- Schoppers, Marcel -- Schroder, Susanne -- Schwenzer, Susanne -- Sebastian Martinez, Eduardo -- Sengstacken, Aaron -- Shterts, Ruslan -- Siebach, Kirsten -- Siili, Tero -- Simmonds, Jeff -- Sirven, Jean-Baptiste -- Slavney, Susie -- Sletten, Ronald -- Smith, Michael -- Sobron Sanchez, Pablo -- Spanovich, Nicole -- Spray, John -- Squyres, Steven -- Stack, Katie -- Stalport, Fabien -- Stein, Thomas -- Stewart, Noel -- Stipp, Susan Louise Svane -- Stoiber, Kevin -- Stolper, Ed -- Sucharski, Bob -- Sullivan, Rob -- Summons, Roger -- Sumner, Dawn -- Sun, Vivian -- Supulver, Kimberley -- Sutter, Brad -- Szopa, Cyril -- Tan, Florence -- Tate, Christopher -- Teinturier, Samuel -- ten Kate, Inge -- Thomas, Peter -- Thompson, Lucy -- Tokar, Robert -- Toplis, Mike -- Torres Redondo, Josefina -- Trainer, Melissa -- Treiman, Allan -- Tretyakov, Vladislav -- Urqui-O'Callaghan, Roser -- Van Beek, Jason -- Van Beek, Tessa -- VanBommel, Scott -- Vaniman, David -- Varenikov, Alexey -- Vasavada, Ashwin -- Vasconcelos, Paulo -- Vicenzi, Edward -- Vostrukhin, Andrey -- Voytek, Mary -- Wadhwa, Meenakshi -- Ward, Jennifer -- Weigle, Eddie -- Wellington, Danika -- Westall, Frances -- Wiens, Roger Craig -- Wilhelm, Mary Beth -- Williams, Amy -- Williams, Joshua -- Williams, Rebecca -- Williams, Richard B -- Wilson, Mike -- Wimmer-Schweingruber, Robert -- Wolff, Mike -- Wong, Mike -- Wray, James -- Wu, Megan -- Yana, Charles -- Yen, Albert -- Yingst, Aileen -- Zeitlin, Cary -- Zimdar, Robert -- Zorzano Mier, Maria-Paz -- New York, N.Y. -- Science. 2013 Jul 19;341(6143):260-3. doi: 10.1126/science.1237961.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. chris.r.webster@jpl.nasa.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23869013" target="_blank"〉PubMed〈/a〉

Description: The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand 〈150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Blake, D F -- Morris, R V -- Kocurek, G -- Morrison, S M -- Downs, R T -- Bish, D -- Ming, D W -- Edgett, K S -- Rubin, D -- Goetz, W -- Madsen, M B -- Sullivan, R -- Gellert, R -- Campbell, I -- Treiman, A H -- McLennan, S M -- Yen, A S -- Grotzinger, J -- Vaniman, D T -- Chipera, S J -- Achilles, C N -- Rampe, E B -- Sumner, D -- Meslin, P-Y -- Maurice, S -- Forni, O -- Gasnault, O -- Fisk, M -- Schmidt, M -- Mahaffy, P -- Leshin, L A -- Glavin, D -- Steele, A -- Freissinet, C -- Navarro-Gonzalez, R -- Yingst, R A -- Kah, L C -- Bridges, N -- Lewis, K W -- Bristow, T F -- Farmer, J D -- Crisp, J A -- Stolper, E M -- Des Marais, D J -- Sarrazin, P -- MSL Science Team -- New York, N.Y. -- Science. 2013 Sep 27;341(6153):1239505. doi: 10.1126/science.1239505.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Aeronautics and Space Administration Ames Research Center, Moffett Field, CA 94035, USA. david.blake@nasa.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24072928" target="_blank"〉PubMed〈/a〉

Description: Samples from the Rocknest aeolian deposit were heated to ~835 degrees C under helium flow and evolved gases analyzed by Curiosity's Sample Analysis at Mars instrument suite. H2O, SO2, CO2, and O2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H2O is bound within an amorphous component of the sample. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO2. Evolved O2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated deltaD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Leshin, L A -- Mahaffy, P R -- Webster, C R -- Cabane, M -- Coll, P -- Conrad, P G -- Archer, P D Jr -- Atreya, S K -- Brunner, A E -- Buch, A -- Eigenbrode, J L -- Flesch, G J -- Franz, H B -- Freissinet, C -- Glavin, D P -- McAdam, A C -- Miller, K E -- Ming, D W -- Morris, R V -- Navarro-Gonzalez, R -- Niles, P B -- Owen, T -- Pepin, R O -- Squyres, S -- Steele, A -- Stern, J C -- Summons, R E -- Sumner, D Y -- Sutter, B -- Szopa, C -- Teinturier, S -- Trainer, M G -- Wray, J J -- Grotzinger, J P -- MSL Science Team -- New York, N.Y. -- Science. 2013 Sep 27;341(6153):1238937. doi: 10.1126/science.1238937.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth and Environmental Sciences and School of Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. leshin@rpi.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24072926" target="_blank"〉PubMed〈/a〉

Description: H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ming, D W -- Archer, P D Jr -- Glavin, D P -- Eigenbrode, J L -- Franz, H B -- Sutter, B -- Brunner, A E -- Stern, J C -- Freissinet, C -- McAdam, A C -- Mahaffy, P R -- Cabane, M -- Coll, P -- Campbell, J L -- Atreya, S K -- Niles, P B -- Bell, J F 3rd -- Bish, D L -- Brinckerhoff, W B -- Buch, A -- Conrad, P G -- Des Marais, D J -- Ehlmann, B L -- Fairen, A G -- Farley, K -- Flesch, G J -- Francois, P -- Gellert, R -- Grant, J A -- Grotzinger, J P -- Gupta, S -- Herkenhoff, K E -- Hurowitz, J A -- Leshin, L A -- Lewis, K W -- McLennan, S M -- Miller, K E -- Moersch, J -- Morris, R V -- Navarro-Gonzalez, R -- Pavlov, A A -- Perrett, G M -- Pradler, I -- Squyres, S W -- Summons, R E -- Steele, A -- Stolper, E M -- Sumner, D Y -- Szopa, C -- Teinturier, S -- Trainer, M G -- Treiman, A H -- Vaniman, D T -- Vasavada, A R -- Webster, C R -- Wray, J J -- Yingst, R A -- MSL Science Team -- New York, N.Y. -- Science. 2014 Jan 24;343(6169):1245267. doi: 10.1126/science.1245267. Epub 2013 Dec 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astromaterials Research and Exploration Science Directorate, NASA Johnson Space Center, Houston, TX 77058, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24324276" target="_blank"〉PubMed〈/a〉

Description: Reports of plumes or patches of methane in the martian atmosphere that vary over monthly time scales have defied explanation to date. From in situ measurements made over a 20-month period by the tunable laser spectrometer of the Sample Analysis at Mars instrument suite on Curiosity at Gale crater, we report detection of background levels of atmospheric methane of mean value 0.69 +/- 0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). This abundance is lower than model estimates of ultraviolet degradation of accreted interplanetary dust particles or carbonaceous chondrite material. Additionally, in four sequential measurements spanning a 60-sol period (where 1 sol is a martian day), we observed elevated levels of methane of 7.2 +/- 2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Webster, Christopher R -- Mahaffy, Paul R -- Atreya, Sushil K -- Flesch, Gregory J -- Mischna, Michael A -- Meslin, Pierre-Yves -- Farley, Kenneth A -- Conrad, Pamela G -- Christensen, Lance E -- Pavlov, Alexander A -- Martin-Torres, Javier -- Zorzano, Maria-Paz -- McConnochie, Timothy H -- Owen, Tobias -- Eigenbrode, Jennifer L -- Glavin, Daniel P -- Steele, Andrew -- Malespin, Charles A -- Archer, P Douglas Jr -- Sutter, Brad -- Coll, Patrice -- Freissinet, Caroline -- McKay, Christopher P -- Moores, John E -- Schwenzer, Susanne P -- Bridges, John C -- Navarro-Gonzalez, Rafael -- Gellert, Ralf -- Lemmon, Mark T -- MSL Science Team -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):415-7. doi: 10.1126/science.1261713. Epub 2014 Dec 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. chris.r.webster@jpl.nasa.gov. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; University of Michigan, Ann Arbor, MI 48109, USA. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. ; Institut de Recherche en Astrophysique et Planetologie, UPS-OMP, CNRS, 31028 Toulouse, France. ; California Institute of Technology, Pasadena, CA 91125, USA. ; Instituto Andaluz de Ciencias de la Tierra [Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad de Granada], Granada, Spain. Division of Space Technology, Lulea University of Technology, Kiruna, Sweden. ; Centro de Astrobiologia, Instituto Nacional de Tecnica Aeroespacial-CSIC, Madrid, Spain. ; Department of Astronomy, University of Maryland, College Park, MD 20742, USA. ; University of Hawaii, Honolulu, HI 96822, USA. ; Carnegie Institution of Washington, Washington, DC 20015, USA. ; Jacobs Technology, NASA Johnson Space Center, Houston, TX 77058, USA. ; Laboratoire Inter-Universitaires Des Systemes Atmospheriques (LISA), UMR CNRS 7583, Paris, France. ; NASA Ames Research Center, Mountain View, CA 94035, USA. ; York University, Toronto, Ontario M3J 1P3, Canada. ; The Open University, Milton Keynes MK7 6AA, UK. ; Space Research Centre, University of Leicester, Leicester LE1 7RH, UK. ; Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico City 04510, Mexico. ; University of Guelph, Guelph, Ontario N1G 2W1, Canada. ; Texas A&M University, College Station, TX 77843, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25515120" target="_blank"〉PubMed〈/a〉

Description: The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550 degrees and 950 degrees C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (+/-0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mahaffy, P R -- Webster, C R -- Stern, J C -- Brunner, A E -- Atreya, S K -- Conrad, P G -- Domagal-Goldman, S -- Eigenbrode, J L -- Flesch, G J -- Christensen, L E -- Franz, H B -- Freissinet, C -- Glavin, D P -- Grotzinger, J P -- Jones, J H -- Leshin, L A -- Malespin, C -- McAdam, A C -- Ming, D W -- Navarro-Gonzalez, R -- Niles, P B -- Owen, T -- Pavlov, A A -- Steele, A -- Trainer, M G -- Williford, K H -- Wray, J J -- MSL Science Team -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):412-4. doi: 10.1126/science.1260291. Epub 2014 Dec 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. paul.r.mahaffy@nasa.gov. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. ; Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85281, USA. Center for Research and Exploration in Space Science and Technology, University of Maryland College Park, College Park, MD 20742, USA. ; Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, USA. ; Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Center for Research and Exploration in Space Science and Technology, University of Maryland College Park, College Park, MD 20742, USA. ; Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, TN 37831, USA. ; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. ; NASA Johnson Space Flight Center, Houston, TX 77058, USA. ; Office of the President, Worcester Polytechnic Institute, Worcester, MA 01609, USA. ; Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Goddard Earth Sciences Technology and Research (GESTAR)/Universities Space Research Association (USRA) NASA Goddard Space Flight Center Greenbelt, MD 20771, USA. ; Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F. 04510, Mexico. ; Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA. ; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA. ; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25515119" target="_blank"〉PubMed〈/a〉

Description: Pyrolysis of soil or rock samples is the preferred preparation technique used on Mars to search for organic molecules up today. During pyrolysis, oxichlorines present in the soil of Mars release oxidant species that alter the organic molecules potentially contained in the samples collected by the space probes. This process can explain the difficulty experienced by in situ exploration probes to detect organic materials in Mars soil samples until recently. Within a few months, the Curiosity rover should reach and analyze for the first time soils rich in sulfates which could induce a different behavior of the organics during the pyrolysis compared with the types of soils analyzed up today. For this reason, we systematically studied the pyrolysis of organic molecules trapped in magnesium sulfate, in the presence or absence of calcium perchlorate. Our results show that organics trapped in magnesium sulfate can undergo some oxidation and sulfuration during the pyrolysis. But these sulfates are also shown to protect organics trapped inside the crystal lattice and/or present in fluid inclusions from the oxidation induced by the decomposition of calcium perchlorate, and probably other oxychlorine phases currently detected on Mars. Trapped organics may also be protected from degradation processes induced by other minerals present in the sample, at least until these organics are released from the pyrolyzed sulfate mineral (~700 °C in our experiment). Hence, we suggest magnesium sulfate as one of the minerals to target in priority for the search of organic molecules by the Curiosity and ExoMars 2018 rovers.

Description: Abstract The Sample Analysis at Mars (SAM) experiment on the NASA Curiosity rover seeks evidence of organic compounds on the surface of Mars. Since the beginning of the mission, various organic molecules have been detected and identified. While several have been demonstrated to be indigenous to the Martian soil and rocks analyzed, others appear to have been produced from sources internal to the experiment. The objective of this study is to build an exhaustive molecular database to support the interpretation of SAM results by identifying all the chemical species produced from Tenax® adsorbents, by determining: (1) the thermal degradation byproducts of Tenax®, (2) the effect of Tenax® conditioning on the formation of Tenax® byproducts, (3) the impact of MTBSTFA or a mixture of MTBSTFA and DMF on Tenax® decomposition, and (4) the reaction between Tenax® and calcium perchlorate. Our results indicate that the by‐products of the SAM trap are due to the impact of trap heating, the impact of the derivatization reagent (MTBSTFA) and the presence of perchlorate in Martian soil. Some of these by‐products are observed in the SAM gas chromatograph mass spectrometer (GCMS) data from Mars.

Description: The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H 2 , SO 2 , H 2 S, NO, CO 2 , CO, O 2 and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. Coevolved CO 2 (160 ± 248 - 2373 ± 820 μgC (CO2) /g), and CO (11 ± 3 - 320 ± 130 μgC (CO) /g) suggest organic-C is present in Gale Crater materials. Five samples evolved CO 2 at temperatures consistent with carbonate (0.32± 0.05 - 0.70± 0.1 wt.% CO 3 ). Evolved NO amounts to 0.002 ± 0.007 - 0.06 ± 0.03 wt.% NO 3 . Evolution of O 2 suggests oxychlorine phases (chlorate/perchlorate) (0.05 ± 0.025 - 1.05 ± 0.44wt. % ClO 4 ) are present while SO 2 evolution indicates the presence of crystalline and/or poorly crystalline Fe- and Mg-sulfate and possibly sulfide. Evolved H 2 O (0.9 ± 0.3 - 2.5 ± 1.6 wt.% H 2 O) is consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H 2 and H 2 S suggest reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, carbonate). SAM results coupled with CheMin mineralogical and APXS elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic-C to support a small microbial population.