Methane find on Mars may be sign of life The Independent

A strong signal of life on Mars has been detected by scientists at the US National Aeronautics and Space Admin- istration (Nasa) and the European Space Agency. Each group has independently discovered tantalising evidence of methane in the Martian atmosphere. Methane, a waste product of living organisms on Earth, could also be a by-product of alien microbes living under the surface of the Red Planet.