Topic: Volcanoes ruled out for Martian methane

[Nemesis]

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New observations of the Martian atmosphere show no trace of sulphurous fumes. The finding rules out active volcanoes as the source of the Red Planet's mysterious methane, but fails to resolve the question of where the methane comes from.

The biggest candidate for non biological origins appears to have been ruled out.

[Commander Maxillius]

Hydran terraforming

[Nemesis]

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To see if methane could be found in Mars-like soil, the investigators collected soil and vapor samples from the arid environment of the Mars Desert Research Station in Utah and then compared them with vapor samples taken from the Idaho High Desert and soil samples from Death Valley, the Arctic and the Atacama desert in Chile.

Three of five vapor samples from the Utah site showed the presence of methane; there was no methane found in any of the vapor samples from Idaho. Similarly, while five of 40 soil samples from Utah produced methane after the addition of growth medium to the samples – indicating that the methane was being given off by a biological organism, most likely a bacterium – none of the other soil samples showed signs of methane production.

Finding methane in the Utah desert is no guarantee that methane-producers exist on Mars, said Miller, who previously has analyzed data from the Viking Lander missions and found that soil samples taken in the 1970s from the Martian surface exhibited a circadian rhythm in what appeared to be nutrient metabolism, much like that present in terrestrial microbes.

However, Miller said, this recent experiment does provide "proof of principle [in that] it improves the case that such bacteria can and might exist on the Martian surface." And, he added, that surely warrants further investigation during future missions to Mars.

In conclusion, the researchers wrote, "The detection of methane, apparently of biological origin, in terrestrial desert regolith bodes well for future biodetection experiments in at least partially analogous Martian environments."

[Nemesis]

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Researchers had thought that meteorites might be responsible for Martian methane levels because when the rocks enter the planet's atmosphere they are subjected to intense heat, causing a chemical reaction that releases methane and other gases into the atmosphere.

However, the new study, by researchers from Imperial College London, shows that the volumes of methane that could be released by the meteorites entering Mars's atmosphere are too low to maintain the current atmospheric levels of methane. Previous studies have also ruled out the possibility that the methane is delivered through volcanic activity.

Continuing to eliminate sources other than life for the methane.

[Johnulus]

Just a thought from my abused brain: Is it possible that the gas is actually seeping out of the planet?. 
The earth has all kinds of natural gas and without an atmosphere there would be nothing left alive on surface to generate oxygen I think the gas would seep out and take the place of oxygen.
If I remember correctly they figure Mars did have an atmosphere at one time which would have given rise to flora and fawna, but then again one can not discount bacterium and fungus, thats what started it all on Earth was it not?.  Oww enough of this brain hates being used just felt like rambling.

[Nemesis]

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Marzo and colleagues found three regions in the planet's northern hemisphere with consistently higher concentrations of methane -- Tharsis, Elysium and Arabia Terrae. Tharsis and Elysium are home to Mars' most massive volcanoes and Arabia Terrae has large quantities of subterranean frozen water.

Methane concentrations are highest in autumn and tail off dramatically in winter. Levels build up again in spring and climb rapidly during summer, causing the gas to spread across the planet, the researchers found.

Interesting.  Seasonal and geographically localized regions of origin.

[Lieutenant_Q]

Seems to me like a way to prove that the is sub-surface liquid water.  The only known substance that expands as it freezes is water.  If there are Methane pockets underneath a subterranean body of water, the methane could slip out when that body of water thaws in the spring and summer, comes out at the highest rate in Autumn, right before it freezes again in the winter blocking any avenue for escape.  Obviously the pockets probably are not very large but the expanding and contracting of sub-surface water would carve out larger pockets than the water would fill in its liquid form.