The Curiosity Rover did not detect any methane on Mars during multiple tests. Previously, methane was detected by earthbound telescopes and the Mars Reconnaissance Orbiter and should have been detected by Curiosity (which can detect down to 1.6 parts per billion).
Why did some experiments detect methane and others didn’t? That’s a good question. There are some possible answers:
Which one is it? A lot of good scientists are debating that very question. The ones who thought they saw methane’s signature in infrared instruments using Earth’s telescopes still think it might be there. Others think they may have seen methane in Earth’s atmosphere. The Mars Reconnaissance Orbiter indicated it saw methane on Mars as well, and it wouldn’t have been fooled by Earth’s methane since it’s in orbit around Mars. Reactions that destroy the methane so quickly would be odd but not impossible. If there were something on Mars that is eating the methane, it would be improbably efficient and active.
For right now, the conclusion seems to be there’s no significant methane on Mars, but everyone will keep looking. If methane were detected on Mars, it would be a good indication that Mars is at least geologically alive and perhaps biologically alive as well. (1)
Thanks to NASA and JPL for the photo from the left Curiosity nav cam used to illustrate this article. The ethane molecule was drawn using ChemDraw for the iPad. Chem Draw is a cool program, although it needs instructions. Perhaps I’ll write them up.
Update: Everyone else has mentioned it, so I thought I should as well: Just because there’s no methane on Mars doesn’t mean there’s no currently living life. Methane is just one of many possible products a lifeform would release. It’s not as bad as the Steelers going 0-3 to start off a season.
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