Organic synthesis on Mars by electrochemical reduction of CO2

• Published in: Science advances Vol. 4; no. 10; p. eaat5118
• Main Authors: Steele, A, Benning, L G, Wirth, R, Siljeström, S, Fries, M D, Hauri, E, Conrad, P G, Rogers, K, Eigenbrode, J, Schreiber, A, Needham, A, Wang, J H, McCubbin, F M, Kilcoyne, D, Rodriguez Blanco, Juan Diego
• Format: Journal Article
• Language: English
• Published: United States AAAS 31.10.2018; American Association for the Advancement of Science
• Subjects: GEOSCIENCES; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; SciAdv r-articles; Space Sciences
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.aat5118

The sources and nature of organic carbon on Mars have been a subject of intense research. Steele et al. (2012) showed that 10 martian meteorites contain macromolecular carbon phases contained within pyroxene- and olivine-hosted melt inclusions. Here, we show that martian meteorites Tissint, Nakhla, and NWA 1950 have an inventory of organic carbon species associated with fluid-mineral reactions that are remarkably consistent with those detected by the Mars Science Laboratory (MSL) mission. We advance the hypothesis that interactions among spinel-group minerals, sulfides, and a brine enable the electrochemical reduction of aqueous CO2 to organic molecules. Although documented here in martian samples, a similar process likely occurs wherever igneous rocks containing spinel-group minerals and/or sulfides encounter brines.The sources and nature of organic carbon on Mars have been a subject of intense research. Steele et al. (2012) showed that 10 martian meteorites contain macromolecular carbon phases contained within pyroxene- and olivine-hosted melt inclusions. Here, we show that martian meteorites Tissint, Nakhla, and NWA 1950 have an inventory of organic carbon species associated with fluid-mineral reactions that are remarkably consistent with those detected by the Mars Science Laboratory (MSL) mission. We advance the hypothesis that interactions among spinel-group minerals, sulfides, and a brine enable the electrochemical reduction of aqueous CO2 to organic molecules. Although documented here in martian samples, a similar process likely occurs wherever igneous rocks containing spinel-group minerals and/or sulfides encounter brines.