Mystery of Missing Martian Methane Deepens 53
astroengine writes "NASA's Mars rover Curiosity has been scouring the thin Martian atmosphere for methane — a potential tracer for the presence of Martian life. However, since the gas also can be produced geologically, any findings promised a meaty debate. That discussion can be shelved, perhaps permanently, new findings from a team of Curiosity scientists shows. The most extensive search yet for methane in Mars' atmosphere has come up empty. 'It's disappointing, of course. We would have liked to get [to Gale Crater] and found lots of methane and measure all the isotopes,' lead researcher Christopher Webster, with NASA's Jet Propulsion Laboratory in Pasadena, Calif., told Discovery News."
Re:What mystery? (Score:5, Informative)
Yes, life can produce methane. Yes, some geological processes can produce methane. Mars has neither... So?
Well, that's the thing. Mars does have methane, we've detected it before. So the mystery is, what happened to the previously detected methane plumes? Why did they disappear?
So now not only do we not know what produced the methane in mars, we additionally don't know why it's no longer doing so. Mystery deepened.
Re:What mystery? (Score:5, Informative)
Some plumes of methane were detected by Mars orbiters and terrestrial telescopes 10 years ago, thus the expectation of the rover detecting the methane.
http://www.space.com/6319-mars-methane-geology-biology.html [space.com]
Re:What mystery? (Score:5, Informative)
There has been plenty of indication that there was methane on Mars, which was an exciting prospect. Quoth the wiki:
http://en.wikipedia.org/wiki/Mars#Atmosphere [wikipedia.org]
In short, orbiters such as the Mars Express detected methane. Methane only has an atmospheric life of a few years, which means if the orbiter detected it then something must be releasing it right now. The amount detected was more than could have been expected from non-living sources, which makes it an indication of life.
If we now can't detect it, that means either all our previous detections were wrong, or the methane has disappeared. Or, of course, that the rover isn't detecting it even though it is still there somewhere. All of which raises more questions than answers. Hence "mystery".