About a third of all life lives in rocks, and I don’t mean your uncle who lives in a cave. I mean actual rocks. Inside of them.
We don’t know a lot about them because they not only tend to live in rocks, these rocks tend to be in places like the bottom of the ocean or near raging volcanoes. But studying extremophiles, as these life forms are called, is worth doing because it yields some really weird stuff.
Specifically Dr. James Holden’s discovery of the methanogen: a microbe that inhales hydrogen and carbon dioxide, and unleashes methane.
To find these little weirdoes, Holden had to send a robot sub to the ocean floor on a visit to the Axial Volcano. He was mostly looking for microbes that live off of hydrogen and the rich nutrients underwater black smokers churn out.
And he found them. In fact, these little buggers are fairly undemanding: Give them 17 micromolar of hydrogen and they’re pretty much good to go. It’s the methanogen that’s particularly interesting, because it feeds off the other’s wastes.
That’s important because it implies there’s a far more complex ecosystem down there than we thought possible. It’s also important because it establishes that a life cycle can be built on more than just oxygen and carbon dioxide… meaning proving this proves there might just be life on Mars.
image courtesy the University of Massachusetts Amherst