Hold your horses (cows?), guys. A new analysis of data from the Curiosity rover found there’s very little methane in the atmosphere of Mars. Methane gas can be a sign of biological activity—of microbial Martians, farting up the atmosphere—so we’re feeling a bit disappointed.
At most, the Martian atmosphere has a methane concentration of 1.3 parts per billion, according to the new analysis. That’s one-sixth as much as previous estimates. The measurement means there’s little chance methane-producing organisms are currently living on Mars, the researchers wrote in a paper they published today in the journal Science.
The data came from Curiosity’s Tunable Laser Spectrometer, which was specially designed to look for methane gas. The instrument has not detected any methane to date. (The team last gave us a similarly sad update on Curiosity’s findings in late 2012).
Previous studies of methane on Mars, conducted using data from telescopes based on Earth and in orbit around the red planet, have found more of the gas. Some analyses have found different concentrations of methane at different sites on the planet, or at different times of year. In 2003, one team reported seeing strong plumes of methane at a different location than where Curiosity sampled. That 2003 study has been controversial among astronomers.
There are micro-organisms that don’t produce methane, so we’re not totally giving up on the possibility of Martians just yet.
Nor does the presence of methane mean there definitely is, or was, something living on a planet. If the Mars air does contain methane, it could come from living organisms, extinct organisms, or geological (not biological) processes within the planet itself. It could have also been carried there from elsewhere in space.