Swamp Gas Found on Mars
The European Space Agency’s Mars Express orbiter has confirmed earlier detections of methane in the Martian atmosphere, according to the BBC News. Because methane could only exist in the atmosphere for a few hundred years, there must be a source that replenishes it. Two sources have been proposed: active volcanos, or living organisms. The BBC is hopeful it is the latter, titling its article, “Methane on Mars could signal life.” Nature Science Update is more cautious, however, asserting that the low levels of methane detected rule out the idea of life spread all over the planet. Instead, it might be leaking from dormant volcanos. Science Now is not sure the methane spectra are definitive yet.
They found methane hissing out of crevices in deep mines on Earth, too (see 04/08/2002 headline), and thought it was a missing link in the evolution of life. The same comments apply.