1. Possible Methane Sources on Mars Mona Houcheime 1,2 Dr. Richard Ulrich 1 1 Arkansas Center for Space and Planetary Sciences, University of Arkansas Fayetteville, AR 72701 2 Department of Biology, San Jose State University, San Jose, CA 95192 Detection of Methane led by three teams: Telescope CH 4 Abundance Vladimir Krasnopolsky-- Catholic Univ. of AmericaCanada-France-Hawaii Telescope 10 ± 3 ppbv Michael Mumma--NASA/Goddard Space Flight CenterCSHELL and Phoenix at Gemini South 10 to 30 ppbv Vittorio Formisano--ESA/Mars Express Planetary Fourier Spectrometer 10 ± 5 ppbv Biotic CH 4 Source? Abiotic CH 4 Source? Future atmospheric and surface studies  Localize methane emissions with high resolution spectrometers such as LIDAR  Search for atmospheric/geologic indicators of weathering  Determine isotopic ratio of atmospheric carbon (biotic origin  low C 13 /C 12 )  Locate hydrothermal vents, hotspots methane hydrate/gas deposits  Drilling investigations to test for presence of past or present life Olivine hydration, in presence of CO 2, is a kinetically and thermodynamically favored (in low-T, high P aqueous environments) reaction:  CH 4 + 2H 2 O (+ weathered products) 4 Presence and abundance of olivine (~30%) at the surface near equatorial regions is consistent with the current atmospheric conditions 3. Conditions support a cold and dry model of the early Martian surface that could have existed for a long time Release of methane from hydrates (high P low T) within the Hydrate Stability Zone (HSZ) by geothermal heat 5 Possible outgassing sources undetected with current spectroscopic instruments Exogenous methane produced by impacts of comets, meteorites, and interplanetary dust (~6%) 1 References 1)Krasnopolsky, V. et al., Icarus, vol. 172, Issue 2, p. 537-547, December 2004 2)Formisano, V. et al., Science, vol. 306, p. 1758-1761, December 3, 2004 3)Bibring, J.P et al., Science, vol. 307, p. 1576-1581, March 11, 2005 4)Oze, C., Sharma, M., Geophysical Research Letters, vol. 32, L10203 (2005) 5)Max, M., Clifford, S., Journal of Geophysical Research, vol.105, no.E2, p.4165- 4171, February 20, 2000 Methanogens olivine Thanks to the National Aeronautics and Space Administration for funding and supporting the Arkansas Space and Planetary Sciences Research for Undergraduates program. I would also like to thank Dr. Ulrich for his assistance. Methane, predominantly produced by biological processes on Earth, is considered a biomarker on Mars Current surface conditions (low T~ 200K, low P~ 6mbar, high UV exposure due to absence of ozone, presence of hydrogen peroxide) hostile to any life-forms on surface Subpermafrost region is the most likely habitat of non-photosynthetic, anaerobic, respiring, methane-producing microorganisms Only a small population would be needed to supply methane at a rate of 4g/sec Metabolic substrates needed for growth of bacterial colonies are present:H 2 O, CO, CO 2, H 2 1 Presence of carbonates supports warm, wet model of early Mars Methane-rich areas were detected in equatorial zones where water (and life-forms) may have existed 95% CO 2 (g) 10 ± 5ppb or 9.1x107 kg CH 4 (g) 2-5% Carbonates * Astro biology Art Gallery http://www.astrobio.net