Martian Methane: Rocky Birth, Then Gone with the Wind?
Meeting Division for Planetary Sciences CAMBRIDGE,U.K.—In the medieval city where Isaac Newton worked on the gravitational laws, about 850 scientists gathered from 4 to 9 September Martian Methane: Rocky Birth, for the 37th meeting of the American Astro- Then Gone With the Wind? nomical Society’s Division for Planetary Sciences. Last year, a spectrometer on board the Euro- which would then be quickly destroyed by the concentrations of some 10 parts per bil- pean Space Agency’s Mars Express space- oxidation, ultraviolet sunlight, and possibly lion seen in the atmosphere. craft detected methane above areas of the also by electrical activity of atmospheric dust. So where does all the methane go? Given martian surface where there also appears to Atreya says basalt reacts with liquid water that methane concentrations vary widely over be subsurface ice (Science, the martian surface, it must be 1 October 2004, p. 29). Many destroyed too quickly for the gas to researchers hailed the find as pos- Methane muddle. Who’s found the right spread out evenly. The explanation sible evidence that bacteria are liv- concentration, Mars Express or Gemini may lie in the electrostatic charg- ing in the ice and producing the South (inset)? ing of dust particles, says Atreya. gas. After all, almost all the In small dust devils and larger dust methane in Earth’s atmosphere is storms, electric fields as strong as produced by living organisms. 25 kilovolts per meter could be Indeed, says planetary scientist produced. Such voltages would Sushil Atreya of the Uni- break up water molecules, and the versity of Michigan, hydroxyl molecules created would Ann Arbor, many then oxidize methane.
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