The Potential for Biologically Catalyzed Anaerobic Methane Oxidation on Ancient Mars
Abstract
This study examines the potential for the biologically mediated anaerobic oxidation of methane (AOM) coupled to sulfate reduction on ancient Mars. Seven distinct fluids representative of putative martian groundwater were used to calculate Gibbs energy values in the presence of dissolved methane under a range of atmospheric CO_2 partial pressures. In all scenarios, AOM is exergonic, ranging from −31 to −135 kJ/mol CH_4. A reaction transport model was constructed to examine how environmentally relevant parameters such as advection velocity, reactant concentrations, and biomass production rate affect the spatial and temporal dependences of AOM reaction rates. Two geologically supported models for ancient martian AOM are presented: a sulfate-rich groundwater with methane produced from serpentinization by-products, and acid-sulfate fluids with methane from basalt alteration. The simulations presented in this study indicate that AOM could have been a feasible metabolism on ancient Mars, and fossil or isotopic evidence of this metabolic pathway may persist beneath the surface and in surface exposures of eroded ancient terrains.
Additional Information
© 2014 Mary Ann Liebert, Inc. Submitted 22 July 2013; Accepted 16 February 2014; Online Ahead of Print: March 31, 2014. J.J.M. would like to thank Dawn Cardace, Andrew Dale, and Megan Newcombe for helpful discussion and consultation and the NETL-National Academy of Sciences Methane Hydrate Research Fellowship for financial support. D.E.L. and J.P.A. would like to acknowledge financial support from the Life Underground NASA Astrobiology Institute (NAI) based at USC. V.J.O. acknowledges the Penn State Astrobiology Research Center NAI.Attached Files
Published - ast.2013.1078.pdf
Supplemental Material - supp_data.pdf
Supplemental Material - supp_table1.pdf
Files
Additional details
- Eprint ID
- 44740
- Resolver ID
- CaltechAUTHORS:20140408-093723442
- NETL-National Academy of Sciences Methane Hydrate Research Fellowship
- Life Underground NASA Astrobiology Institute (NAI)
- Penn State Astrobiology Research Center NAI
- Created
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2014-04-08Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences