Abiotic Input of Fixed Nitrogen by Bolide Impacts to Gale Crater During the Hesperian: Insights From the Mars Science Laboratory

• Published in: Journal of Geophysical Research: Planets
• Main Authors: Navarro-González, Rafael, Navarro, Karina F., Coll, Patrice, Mckay, Christopher P., Stern, Jennifer C., Sutter, Brad, Archer Jr, P. Douglas, Buch, Arnaud, Cabane, Michel, Conrad, Pamela, G., Eigenbrode, Jennifer L., Franz, Heather, B., Freissinet, Caroline, Glavin, Daniel P., Hogancamp, Joanna V., Mcadam, Amy, Malespin, Charles A., Martin-Torres, F. Javier, Ming, Douglas W., Morris, Richard V., Prats, Benny, Raulin, François, Rodríguez-Manfredi, José Antonio, Szopa, Cyril, Zorzano-Mier, María-Paz, Mahaffy, Paul R., Atreya, Sushil, Trainer, Melissa, Grady, Vasavada, Ashwin
• Other Authors: Instituto de Ciencias Nucleares Mexico, Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), 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), NASA Goddard Space Flight Center (GSFC), Jacobs Technology ESCG, NASA Johnson Space Center (JSC), NASA, 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)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Computer Science, Electrical and Space Engineering Luleå, Luleå University of Technology = Luleå Tekniska Universitet (LUT), Centro de Astrobiologia Madrid (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC), Department of Atmospheric, Oceanic, and Space Sciences Ann Arbor (AOSS), University of Michigan Ann Arbor, University of Michigan System-University of Michigan System, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Yellowknife; Yellowknife Bay
• Online Access: https://insu.hal.science/insu-01962074; https://insu.hal.science/insu-01962074/document; https://insu.hal.science/insu-01962074/file/Navarro-Gonz-lez_et_al-2019-Journal_of_Geophysical_Research__Planets.pdf; https://doi.org/10.1029/2018je005852

International audience Molecular hydrogen (H 2 ) from volcanic emissions is suggested to warm the Martian surface when carbon dioxide (CO 2 ) levels dropped from the Noachian (4100 to 3700 Myr) to the Hesperian (3700 to 3000 Myr). Its presence is expected to shift the conversion of molecular nitrogen (N 2 ) into different forms of fixed nitrogen (N). Here we present experimental data and theoretical calculations that investigate the efficiency of nitrogen fixation by bolide impacts in CO 2 ‐N 2 atmospheres with or without H 2 . Surprisingly nitric oxide (NO) was produced more efficiently in 20% H 2 in spite of being a reducing agent and not likely to increase the rate of nitrogen oxidation. Nevertheless, its presence led to a faster cooling of the shockwave raising the freeze‐out temperature of NO resulting in an enhanced yield. We estimate that the nitrogen fixation rate by bolide impacts varied from 7×10 ‐4 to 2×10 ‐3 g N Myr ‐1 cm ‐2 , and could imply fluvial concentration to explain the nitrogen (1.4±0.7 g N Myr ‐1 cm ‐2 ) detected as nitrite (NO 2 – ) and nitrate (NO 3 – ) by Curiosity at Yellowknife Bay. One possible explanation is that the nitrogen detected in the lacustrine sediments at Gale was deposited entirely on the crater's surface, and was subsequently dissolved and transported by superficial and ground waters to the lake during favorable wet climatic conditions. The nitrogen content sharply decreases in younger sediments of the Murray formation suggesting a decline of H 2 in the atmosphere, and the rise of oxidizing conditions causing a shortage in the supply to putative microbial life.