This diagram shows possible ways by which methane might incorporate into Mars’ atmosphere (sources) and disappear from the atmosphere (sinks). Image credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan
One small piece of the Mars methane mystery may have just been solved.
NASA’s Curiosity rover has spotted multiple surges of methane in Mars’ air over the past few years – most recently in June 2019, when levels of the gas inside the Red Planet’s Gale Crater spiked to 21 parts per billion per unit volume (ppbv).
That’s far higher than background methane levels on Gale’s floor, which Curiosity has determined range seasonally from 0.24 ppbv to 0.65 ppbv.
Scientists don’t know what’s producing this methane, or where exactly it’s coming from. But they’re keen to find out, because the gas is a possible sign of life. More than 90 perent of the methane in Earth’s air, for example, was produced by microbes and other organisms.
A recent study may help researchers narrow the hunt. Scientists estimated the methane content of typical Red Planet rocks by analysing Mars meteorites and native basalt and sedimentary rocks here on Earth – stand-ins for their Martian counterparts.
The team then calculated how much of this methane could be ...