Reconciling methane variations on Mars

While we're on the subject, there's that seasonal methane we've detected in the martian atmosphere. Since the days of the Mariner and Viking, to Opportunity and Spirit, we've encountered these ambiguous signs of something...anything... on the edge of life, even if it turns out microscopic or something different altogether, like Archaea, do we want to risk a War of the Worlds scenario?

If it's alive on Mars, chances are its an endangered species.

ESA: Since the discovery of its presence in the Martian atmosphere, methane has remained an intriguing atmospheric component which source (either of biotic or abiotic origin) is not yet fully understood. The recently reported variations in the concentration of atmospheric methane have proven difficult to explain with 3-D numerical models of the atmosphere that include the known chemical and physical processes. In a paper published this week in Nature, Franck Lefevre and Francois Forget present their study to derive the implications of the observed methane concentrations on Mars and their variability. They conclude that there needs to be both an intense localised source of methane and a destruction mechanism that is much more efficient than the known atmospheric processes that break down methane. Further, if this efficient destruction of methane occurs only close to the surface, these findings imply a very harsh environment for organic molecules to survive on the surface of Mars.

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