It could be a blow for those who believe there’s life on the Red Planet. Spongy minerals at the surface, not living organisms, could be releasing Mars’s mysterious methane.
Methane gas, which chiefly emerges from biological processes, was identified on Mars in 2003. Since then, measurements by NASA’s Curiosity rover and others have shown that on any given day, methane exists in small but significant quantities, and occasionally jumps by a factor of 10.
Because it doesn’t hang around for long, something must still have been creating it.
“The cool thing about methane is that if you see it in the atmosphere that means it’s fresh – it’s being produced now,” says David Bish, a geologist at Indiana University in Bloomington.
But a new study is hypothesising that the methane is actually very old and has been locked away, perhaps for billions of years, occasionally pulsing into the atmosphere.