Mars Curiosity Rover detects 'possible hints of life' on Mars

Nasa’s Curiosity Rover has detected methane on Mars – a gas that could hint at past or present life on the red planet.

18:10 17 December 2014

Nasa’s Curiosity Rover has detected very low-level amounts of methane on Mars that could signal possible hints of prior life in the planet. It also monitored a number of short-lived spikes that are 10 times higher.

Curiosity scientist Sushil Atreya said it was possible that so-called clathrates were involved.

"These are molecular cages of water-ice in which methane gas is trapped. From time to time, these could be destabilised, perhaps by some mechanical or thermal stress, and the methane gas would be released to find its way up through cracks or fissures in the rock to enter the atmosphere," the University of Michigan professor told BBC News.

"The background figure suggests there are about 5,000 tonnes of methane in the atmosphere," said Dr Chris Webster, from Nasa's Jet Propulsion Laboratory, who led the investigation.

"You can compare that with Earth where there are about 500 million tonnes. The concentration here at Earth is about 1,800 parts per billion by volume."

In the last two months, Curiosity has monitored spikes of methane on four occasions. They varied between about 7 and 9 parts per billion by volume.