Scientists have discovered plumes of methane rising from the surface of Mars, which is consistent with the existence of microbes:
The researchers today today are reporting that in 2003 and 2006, they recorded plumes of methane rising from the surface of the Red Planet. Working back from their measurements of methane in the air, the researchers pinpointed some particular spots on Mars where the methane came from. And it’s a lot of methane they’re talking about–19,000 metric tons of the stuff in one plume. It’s coming out of Mars at the same rate seen at methane-producing spots on Earth.
Those places on Earth happen to be places where microbes are churning the gas out. There might be other ways of getting plumes of methane into the air–generating it from magma, for example. But in a paper published today by Science, Mumma and his colleagues point to the possibility that microbes buried a mile or two under the surface of Mars might be responsible.
There are also nonbiological possibilities, so we need to restrain our excitement a wee bit. Still, it's hard to ignore what could be the most momentous event in science since Einstein's theories.