Methane has been discovered on Mars, raising the possibility of past or present life on the Red Planet, scientists said today. The gas was detected recently using the Planetary Fourier Spectrometer (PFS)
on the European Space Agency orbiter Mars Express.
Dr Vittorio Formisano, principal investigator of PFS, said the finding could either be evidence of life or of volcanic activity. Many more observations and studies were required to identify the source of the
methane, he added.
"Eventually we shall perhaps be able to identify the source of methane," said Dr Formisano.
"The source is going to be a rather big issue. The source could be either simply volcanic activity, or life of biological origin.
"I am not stating that there is life now. There is no conclusion yet." The scientist said methane could only exist for a few hundred years in the Martian atmosphere.
This meant there could still be life or volcanic activity now on the Red Planet.
Dr Formisano added: "In my opinion it is most likely of volcanic origin, but I need many more observations.
"For the moment, we can only say there is evidence of methane, and we have the possibility of accumulating more data and eventually finding the source."
Professor Colin Pillinger, chief scientist of missing Mars probe Beagle 2, said the discovery could be evidence of "past life or even current life".
He said he believed the gas was unlikely to be the production of volcanic activity alone.
Scientists on Mars Express have previously detected frozen water at the Martian south pole, which they said confirmed the possibility that Mars once harboured life.
Last week, Nasa announced that its Mars rover Opportunity had discovered what was once a salty sea on the Red Planet.