There was a big stir when reports emerged that they detected methane on Mars. But there was a problem: it could not be ruled out that its sensors were wiggy, or something was misinterpreted.
On 16 June 2013, a day before Curiosity detected methane in the same region, the European Space Agency’s Mars Express mission, in orbit around the Red Planet, caught a whiff of the stuff near the Gale Crater – the region explored by Curiosity.
Other instruments have detected methane on Mars. But this is the first time two separate pieces of equipment have detected methane (CH4) in the same region at the same time.
“Despite various detection’s reported by separate groups and different experiments, and although plausible mechanisms have been proposed to explain the observed abundance, variability and lifetime of methane in the current Martian atmosphere, the methane debate still splits the Mars community.”
“Prior to our study, methane detections on Mars were not confirmed by independent observations. This latest finding constitutes the first independent confirmation of a methane detection.”
There are geological processes that can generate methane abiotically. On gas and ice giants such as Jupiter, Saturn, Uranus and Neptune, plenty of methane is produced via chemical processes.
Pluto has methane ice. Saturn’s moon Titan has lakes of liquid methane. The stuff isn’t exactly rare in the Solar System.
On Mars, too, the global concentration is minuscule compared to Earth’s – it appears in bursts, with a global average of just 10 ppbv. But figuring out where the Martian methane came from, and how, will tell us something new and exciting about the Red Planet – even if that source is not microbes.
According to the researchers, transient events in a fault region near the Gale Crater are the most likely place of methane release. That could also explain why it disappears and reappears so peculiarly.
“Since permafrost is one of the best seals for methane, it is possible that bulk ice in the MFF may trap and seal subsurface methane.
We won’t know until we can go look – but now we know that further investigation would absolutely be worthwhile.
Meanwhile, the search for methane is ongoing. The PFS instrument continues to monitor the Martian atmosphere, and its entire data backlog will be reanalyzed using the team’s new techniques.