Molecular Monday: Mars Burps Methane

Happy New Year’s, and happy Molecular Monday too! I can’t think of a better way to start off 2018 than with a blog post about molecules. Well, no… I probably could, but my schedule says this is what I’m supposed to blog about today, so here we are!

If you’re looking for life on other planets, one of the most common pieces of advice you’ll get is “follow the water.” That is, of course, assuming you can find any liquid water in the first place. But maybe another option is to follow the methane.

The planet Mars seems to have a bit of a methane mystery going on. Mars will sit there, all quiet and normal, for years at a time, but then suddenly…

… and then suddenly all this methane shows up in the planet’s atmosphere.

The most notable of these methane burps occurred in late 2013 and early 2014, when the Curiosity rover started detecting methane levels ten times higher than normal. Where did all this methane come from?

One boring possibility is that it came from the rover itself, a result of some kind of leak. It’s also possible that a meteorite just happened to land near Curiosity, and that this meteorite just happened to be carrying a lot of organic material. Or maybe there was some kind of surprise geological activity nearby that vented methane from somewhere underground.

But the most intriguing possibility is that the methane was produced by biological activity. That is, after all, how most atmospheric methane is produced on Earth. And I recently found this paper offering a possible way to determine once and for all (maybe, hopefully, fingers crossed) if Mars’s methane really does come from a biological source.

From what I gather, having only skimmed through this paper (sorry, I was trying to read this on New Year’s Eve, and there were margaritas), the key is to follow the methane then follow the hydrogen. So the next time Mars burps up some methane, the ratio of methane to hydrogen in the air might reveal the methane’s true source.