Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

• Published in: Journal of Geophysical Research: Planets
• Main Authors: Freissinet, Caroline, Glavin, D. P., Mahaffy, Paul R., Miller, K. E., Eigenbrode, J. L., Summons, R. E., Brunner, A. E., Buch, A., Szopa, Cyril, Archer, P. D., Franz, H. B., Atreya, S. K., Brinckerhoff, W. B., Cabane, Michel, Coll, Patrice, Conrad, P. G., Des Marais, D. J., Dworkin, J. P., Fairén, A. G., François, P., Grotzinger, J. P., Kashyap, S., ten Kate, I. L., Leshin, L. A., Malespin, C. A., Martin, M. G., Martin-Torres, F. J., Mcadam, A. C., Ming, D. W., Navarro-González, R., Pavlov, A. A., Prats, B. D., Squyres, S. W., Steele, A., Stern, J. C., Sumner, D. Y., Sutter, B., Zorzano, M.-P.
• Other Authors: NASA Goddard Space Flight Center (GSFC), Department of Earth, Atmospheric and Planetary Sciences MIT, Cambridge (EAPS), Massachusetts Institute of Technology (MIT), Center for Research and Exploration in Space Science and Technology GSFC (CRESST), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA Johnson Space Center (JSC), NASA, Department of Atmospheric, Oceanic, and Space Sciences Ann Arbor (AOSS), University of Michigan Ann Arbor, University of Michigan System-University of Michigan System, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), NASA Ames Research Center (ARC), Centro de Astrobiologia Madrid (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Cientificas = Spanish National Research Council (CSIC), Department of Astronomy Ithaca, Cornell University New York, Division of Geological and Planetary Sciences Pasadena, California Institute of Technology (CALTECH), Department of Earth Sciences Utrecht, Universiteit Utrecht / Utrecht University Utrecht, Rensselaer Polytechnic Institute (RPI), Goddard Earth Sciences and Technology and Research (GESTAR), NASA-Universities Space Research Association Washington (USRA), Department of Chemistry CUA, Catholic University of America, Department of Computer Science, Electrical and Space Engineering Luleå, Luleå University of Technology (LUT), Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Cientificas = Spanish National Research Council (CSIC)-Universidad de Granada = University of Granada (UGR), Astromaterials Research and Exploration Science (ARES), NASA-NASA, Instituto de Ciencias Nucleares Mexico, Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Geophysical Laboratory Carnegie Institution, Carnegie Institution for Science, Department of Earth and Planetary Science UC Berkeley (EPS), University of California Berkeley (UC Berkeley), University of California (UC)-University of California (UC), NASAFrench Space Agency (CNES)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Surface materials and properties; Volcanism; Composition; Erosion and weathering; Mars; [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]; [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]; Yellowknife; Yellowknife Bay
• Online Access: https://insu.hal.science/insu-01218165; https://insu.hal.science/insu-01218165/document; https://insu.hal.science/insu-01218165/file/Freissinet_et_al-2015-Journal_of_Geophysical_Research__Planets.pdf; https://doi.org/10.1002/2014JE004737

International audience The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150–300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.