Martian Methane May Come From Rocks

An anonymous reader writes "When methane was found in the Martian atmosphere last year, some scientists thought this was indirect evidence of methane-producing bacteria. But minerals such as olivine can create methane in a process known as serpentinization. Geologists calculated that a global, 50-centimetre-thick layer of olivine could account for the methane. One geologist said, 'I'd love to see bugs, but you can't just go on hope. You have to consider the geological options.' Other scientists are unsure whether methane on Mars even exists."

Comments

Serpentinization: hint of water

[helioquake]

Serpentinization requires water to seep through rocks and to get oxidized. If this new interpretation of the existence of methane is indeed correct, then it clearly implies the existence of the large body of water in the recent past (or at present).

So in either way it turns out, this is a cool finding.

/i do have to wonder sometimes, though, how narrow-minded those astrophysicists/planetary scientists are, as opposed to those geologists who have to work really hard to match their theory/experiment with the abundant amount of sample data points on earth.

mars is a exobiological rorschach test

[eexlebots]

I mean, one scientist looks at a meteor and says, "Oh good there is ancient Mars life in it, "and another looks at the same meteor and says, "Oh no that is a geologic process." One looks at the Viking lander data and says, "Oh check it out life!" and another says, "Nope just an unforseen nonbiotic chemical reaction." Now it is the same argument with Methane. Jeeze, we should just send some dudes over there and get this over with already...

Re:Viking Landers

[Kymermosst]

It has been known for some considerable time, as a result of experiments by the Viking Landers, that the soil had some interesting chemical properties. It is hardly news. However, methane from the rocks and clay cannot be the source, as the methane has been seen concentrated in small regions, whereas the rocks and soil are fairly uniform across the planet.

Obvious solution: The methane isn't being formed at the surface.

Serpentinization only requires that the olivine (more likely, peridotite - an olivine/pyroxene rock) be moved to cooler temperatures and lower pressures, with a bit of water to make the ions move.

So, in your "small regions" where the methane is concentrated, you have some subsurface olivine and some water getting to it.

Regarding that uniform rock and soil on the martian surface, consider flood basalts over eastern Oregon and Washington. The surface is made up of basalt, yes. However, underneath all that basalt, in many areas, is material that was buried by it.