Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere

Details Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere

Dec 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufm.p23e..10k&link_type=abstract

American Geophysical Union, Fall Meeting 2011, abstract #P23E-10

Biology

[0330] Atmospheric Composition And Structure / Geochemical Cycles, [0406] Biogeosciences / Astrobiology And Extraterrestrial Materials, [6005] Planetary Sciences: Comets And Small Bodies / Atmospheres, [6225] Planetary Sciences: Solar System Objects / Mars

Scientific paper

Almost a decade ago three independent groups of scientists announced the discovery of methane in the atmosphere of Mars at concentrations up to several tens of parts per billion (Mumma et al., 2003; Krasnopolsky et al., 2004; Formisano et al., 2004). Since then there has been an ongoing debate as to whether the formation processes are of geological or biological origin because methane is considered to be unstable in the Martian atmosphere, with a lifetime of a few hundred years or even less (Lefèvre and Forget 2009). Thus a process on or below the planet surface must be continuously replacing it. Furthermore methane release appears to be non-uniform over the planet because it was observed as plumes over certain regions in Northern Summer (Mumma et al. 2009). A biological origin would provide support for the theory of some form of life or potential life on the planet, whereas a geological origin would imply that there is unusual geological activity occurring on it. Almost ten possible mechanisms may be involved in the production of methane on Mars (Schürger et al. 2011) including subsurface clathrates and serpentinization of olivine, geothermal outgassing or biological methanogenic processes. However, all hypotheses explaining methane formation on Mars also have shortcomings. For example, methane release from meteorites as a product of ablation and pyrolysis upon atmospheric entry of carbonaceous chondrites was estimated to account only for a negligible fraction of Martian methane (Court and Sephton 2009). In this presentation we show that methane is produced in significant quantities from the carbonaceous chondrite Murchison (CM2) when exposed to ultraviolet radiation similar to Martian surface conditions. Emission rates depend on temperature and atmospheric pressure. Stable carbon and hydrogen isotope analyses of methane released from Murchison were also determined and confirm that the methane emitted from Murchison is of extraterrestrial origin. Our results might have important implications for our understanding of the generation of methane on Mars because meteoritic material (mostly micrometeorites resembling in composition the CM meteorites) containing a few percent organic matter is estimated to reach the Martian surface at high rates (Flynn and McKay, 1990), resulting in Martian soil that contains large amounts of meteoritic debris. Thus our results provide an explanation for a potentially significant contribution to Martian atmospheric methane but may also explain some local sources and seasonal variations such as the recently observed methane plumes (Mumma et al. 2009). Court, R.W., Sephton, M.A. (2009) Earth and Planetary Science Letters 288, 382-385. Formisano, V. et al. (2004). Science 306, 1758-1761. Flynn, G.J., McKay, D.S., (1990). J. Geophys. Res.-Solid 95, 14,497-14,509. Lefèvre, F., Forget, F., (2009) Nature 460, 720-723. Krasnopolsky, V.A. et al. (2004) Icarus 172, 537-547. Mumma, M. J. et al. (2003) Bull. Am. Astron. Soc. 35, 937. Mumma, M.J. et al. (2009) Science 323, 1041-1045. Schuerger, A.C. et al. (2011) Icarus 213, 393-403.

Affiliated with

Also associated with

No associations

Rating

Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methane Emission from the Murchison Meteorite Induced by Ultraviolet Radiation and its Potential Impact on the Martian Atmosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-870051