Gas may yield clue to life on Mars The Guardian

Scientists yesterday confirmed the presence of methane on Mars, raising two possibilities – volcanos, or life on the red planet. “Methane should be short-lived in that atmosphere. It should last for less than a few hundred years,” Andrew Coates, of the Mullard space science laboratory at University College London, told the British Association science festival in Exeter. “So there must be a very recent source, perhaps even a current source. The two possible sources could be volcanism – very recent or current volcanism – or life. All life as we know it on Earth, even down to the tiniest microbe, produces methane as a byproduct.”