The presence of methane on Mars could be the promise of past or present life on the Red Planet. NASA's Curiosity rover detected short spikes that are 10 times higher than the usual background levels, according to The Daily Star.

Ninety-five percent of methane on Earth comes from microbial organisms, so the suggestion seems valid. The source of the methane on Mars is still unknown, but possibly thought to be disturbed underground stores.

"These are molecular cages of water-ice in which methane gas is trapped," said Curiosity scientist Sushil Atreya. "From time to time, these could be destabilized, 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."

How did the methane get into those clathrate stores? Martian bugs, perhaps, or a process called serpentinisation, when methane is produced from interactions with certain rocks. They are all just guesses, but the big news is: Curiosity was able to detect the gas.

"The background figure suggests there are about 5,000 tonnes of methane in the atmosphere," said Chris Webster from Nasa's Jet Propulsion Laboratory. "You can compare that with Earth where there are about 500 million tonnes."

The spikes in methane occurred four times in the last two months, according to The Daily Star. The gas is possibly being emitted from a nearby crater.

"It's a big day for us - it's a kind of crowning moment of 10 years of hard work - where we report there is methane in the atmosphere and there are also organic molecules in abundance in the sub-surface," said Curiosity project scientist John Grotzinger.