Signs of life found on Mars
18 december 2014, 11:11 1414 views
Nasa's Curiosity rover has detected methane on Mars - a gas that could hint at past or present life on the planet.
The robot sees very low-level amounts constantly in the background, but it also has monitored a number of short-lived spikes that are 10 times higher.
Methane on the Red Planet is intriguing because here on Earth, 95% of the gas comes from microbial organisms.
Researchers have hung on to the hope that the molecule's signature at Mars might also indicate a life presence.
The Curiosity team cannot identify the source of its methane, but the leading candidate is underground stores that are periodically disturbed.
The question remains, of course, of how the methane (CH4) got into the clathrate stores in the first place.
It could have come from Martian bugs; it could also have come from a natural process, such as serpentinisation, which sees methane produced when water interacts with certain rock types.
At the moment, it is all speculation. But at least Curiosity has now made the detection.