The Search for Life on Mars
Abstract
The abiotic and biological pathways for methanogenesis on Mars are surprisingly similar. Both mechanisms use CO_2 and H_2 as starting materials and result in the production of CH_4. However, the geochemical pathway has a high kinetic barrier and the reaction is slow. A biological pathway quickens this process. The total flux of 1.7x10^7 mol year^(-1) that is needed to maintain the observed CH_4 in steady state in the atmosphere is examined in the context of fluxes of He from the interior of the planet and photochemical production of H_2 in the atmosphere. In situ analysis of the isotopologues of CH_4 and estimates of the relative abundances of members of the alkane family, as well as of CH_4:H_2 ratios and species such as acetic acid, could be used to discriminate between abiotic and biological sources on Mars. Discerning how methane generation emerged on the evolutionarily retarded Mars may open a window on how life originated so long ago on our own planet.
Additional Information
© 2010 Journal of Cosmology. Posted January 31, 2010. YLY acknowledge supported by NASA grant NASA5-13296 and the Virtual Planetary Laboratory at the University of Washington. MJR's research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration for Astrobiology : Exobiology and Evolutionary Biology and supported by NASA's Astrobiology Institute (Icy Worlds). We thank N. Heavens, F. Li, X. Zhang, M. Gerstell and M. Line for reading and improving the manuscript.Additional details
- Eprint ID
- 48859
- Resolver ID
- CaltechAUTHORS:20140825-141003133
- NASA5-13296
- NASA
- University of Washington Virtual Planetary Laboratory
- NASA/JPL/Caltech
- NASA Astrobiology Institute
- Created
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2014-08-25Created from EPrint's datestamp field
- Updated
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2020-03-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences