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> The reason this news registered among scientists is that methane is often a sign of life; although the gas can be produced by various chemical reactions, most
by wahern 7y ago
> The reason this news registered among scientists is that methane is often a sign of life; although the gas can be produced by various chemical reactions, most of it comes from animate beings.
This doesn't sound right at all. There are literally lakes of methane on Titan. The atmospheres of Jupiter, Saturn, Uranus, and Neptune all contain significant methane--it's what makes Uranus and Neptune blue. Pluto has methane ice.
IIRC from the original reporting, some recent research suggested that there's more methane than contemporary geological models of Mars predict. Which likely says more about the [non-biological] deficiencies in those models than it does the likelihood of life.
I'm not an astro-anything, so feel free to correct me. But it's telling that the interviewee never comes close to confirming the reporter's claims; they're simply quoted as saying, "I think probably many people would like the idea of methanogens on Mars", and "the idea that they might be related to methanogens on Earth is not crazy." Isaac Chotiner is a name I'll try to remember so I can avoid his articles.
- BurningFrog 7y agoThere is ancient methane in those places. But something on Mars is producing methane. Methane breaks down pretty fast in Mars' atmosphere, and yet it reappears there occasionally. That can certainly have non life explanations. But they're fairly exotic.
- jvanderbot 7y agoIIRC, methane should not persist on Mars, and theres not been a global phenomenon detected that can explain its occasional detection. Therefore, transient detections are considered indicators of possible life, since nothing else seems to explain it. It's not that it's rare everywhere, it's that it's rare on Mars.
- mturmon 7y agoThe author (Chotiner) has indeed made a mis-statement about the state of knowledge on planetary CH4, but that doesn't pertain directly to most of the article's content, which is about DNA/RNA. As you point out, the state of Mars CH4 is quite complex and extremely controversial, with 3 different measurements (Curiosity + 2 orbiters), low concentrations observed (~10 ppb) and multiple physical processes going on. Here's a pretty good recent summary: https://www.abc.net.au/news/science/2019-04-02/mars-express-confirms-methane-spike-detected-by-curiosity-rover/10563160 https://www.abc.net.au/news/science/2019-04-02/mars-express-... The DNA-sensing instrument that's being prototyped is here: http://setg.mit.edu http://setg.mit.edu