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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."
"Cows on Mars." *dunh dunh dunnnhhh*
Look, if a cow can jump over the Moon, it's not much of a stretch to think they can get to Mars. Getting out of the Earth's gravity well is most of the challenge, really.
Maybe that layer is planet wide, and part of a larger living organism that will one day be calling us ugly bags of mostly water.
Well someone had to say it...
alek writes "When methane was found in the Terrestial atmosphere last year, some scientists thought this was indirect evidence of methane-producing bacteria. But animals such as bovines can create methane in a process known as breaking wind. Animalogists calculated that a global herd of 50,000 bovines could account for the methane. One animalogist said, 'I'd love to see udders, but you can't just go on hope. You have to consider the back-end options.' Other scientists are unsure whether methane on Earth even comes from cows."
Hulk SMASH Celiac Disease
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).
/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.
So in either way it turns out, this is a cool finding.
my pet rock was also very flatulent
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...
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Well, hell a 50cm layer of olivine covering a whole goddamn planet is totally feasible.
I wonder why they didn't think of that before?
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
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.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Here's the abstract of the original paper. I can't give a link because it requires a subscription to Science, but I think this is enough.
Detection of Methane in the Atmosphere of Mars
Vittorio Formisano,Sushil Atreya, Thérèse Encrenaz, Science, Vol 306, Issue 5702, 1758-1761, 3 December 2004
We report a detection of methane in the martian atmosphere by the Planetary Fourier Spectrometer onboard the Mars Express spacecraft. The global average methane mixing ratio is found to be 10 ± 5 parts per billion by volume (ppbv). However, the mixing ratio varies between 0 and 30 ppbv over the planet. The source of methane could be either biogenic or nonbiogenic,including past or present subsurface microorganisms, hydrothermal activity, or cometary impacts.
Later in the article, they expand on what they mean by "hydrothermal activity."
On the other hand, methane could have been formed by magmatic processes or stored in methane hydrates for later release to the atmosphere. Terrestrial volcanoes are not a big source of methane, and large-scale volcanism has not taken place on Mars for over 100 million years. However, small-scale outgassing of methane cannot be ruled out. A potentially larger source of methane than volcanism may come from the alteration of basalt at a temperature <150C, a process that also results in the wet-phase conversion of original CO2 into CH4 in a subpermafrost aquifer. In their chemical equilibrium computer model, Wallendahl et al. calculate that as much as 0.2 bar, ~1015 tons, of CH4 could have been produced if the only source of C in this region was the CO2 initially present in the crustal pores. Methane could have been sequestered in stable methane hydrate and gradually risen to the planet's surface. The rate of release to the atmosphere is unknown, but if one assumes that leaking has been taking place at a uniform rate over time, it would amount to ~200,000 tons year-1, which is much greater than the 100 tons or so per year needed to maintain a steady-state mixing ratio of 10 ppbv of CH4 on Mars today. Even if methane from the hydrate is being released at a rate that is a factor of 1000 slower, it would still be sufficient to account for the observations. Finally, recent laboratory experiments confirm abiogenic generation of methane in mineral-catalyzed hydrothermal reactions of CO2 and H2O at 390C and 400 bars, conditions that are likely to be encountered in subpermafrost aquifers or deep under the polar ice on Mars. Moreover, the catalyst used in the experiment--Fe-Cr oxide--is also believed to be present in the martian rocks.
Note that Olivine is Magnesium Iron Silicate (http://mineral.galleries.com/minerals/silicate/ol ivine/olivine.htm), so that's not the same as the Fe-Cr considered here, but it's not all that far a stretch either.
--Greg
Olivine is green. See this picture of an isolated, but still somewhat famous, green-sand beach in Hawaii
e ach.jpg i th/hawaii02_images2/greensandbeach.jpg
It is green because of all the olivine in the sand, been there myself a few times:
http://www.letsgo-hawaii.com/beaches/GreenSand2_b
http://artemis.austincollege.edu/acad/bio/sgoldsm
If there really is that much olivine on the planet, we are going to have change the nickname from "the red planet" to "the christmas planet."
When information is power, privacy is freedom.
Other scientists are unsure whether methane on Mars even exists.
While many philosophers are unsure whether Mars exists at all, or if it's just a figment of thier imagination.
"Your superior intellect is no match for our puny weapons!"
Did anyone else read "50 centemetre layer of olvaltine?"
comes from Uranus. [ducks]
Yeah, but re-entry is a bitch. How well do you like your steaks done? ^_^
Please help metamoderate.
There is a hypothesis doing the rounds that nanobacterial metabolism is responsible for depositing mineral plaques from solution.
r ia+olivine&btnG=Search&meta=
http://www.google.com.au/search?hl=en&q=nanobacte
Notably, the microfossils found in the martian meteorite are thought to be of nanobacterial origin.
"ARR! ARRR! This dictionary is edited by the section of Lexigography and Language studies. The Nynorsk Dictionary is published by The Norwegian Society."
Somehow, doesn't seem like the kind of thing a ferocious viking would say, now does it?
What process does produce the methane then?
Olivine+Water -> Serpentine+Methane+?
So:
x*(Mg2SiO4) + y*(Fe2SiO4) + z*(H2O) -> a*(several longish formulas for different kinds of Serpentine) + CH4 + ?
So where's the carbon coming from? I don't see any on the left side? All nice and pretty but carbon isn't all that common outside Earth, and is fundamental for building proteins - that is earth-like life, and there's no methane without carbon.
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