NASA’s Curiosity rover detected a strange burst of methane gas in the atmosphere on Mars, along with other organic chemicals in rocks on the planet’s surface. These findings are raising new questions about the planet’s habitability today as well as in the past.
Using its onboard Sample Analysis at Mars (SAM) laboratory, the rover “sniffed” more than a dozen samples of the Martian atmosphere over a 20-month period. Grotzinger and his team found that methane levels shot up tenfold to an average of seven parts per billion over two months in late 2013 and early 2014, according to NASA.
The researchers aren’t sure what caused the burst, but they’ve offered two potential explanations: an interaction between water and rocks called serpentization, or methane-belching microbes. Anaerobic bacteria produce around 95 percent of the methane on Earth.
Curiosity found other organic (carbon-containing) molecules in powder collected from drilling into an ancient rock called Cumberland.
The researchers say this is the first definitive evidence of organics found on the surface of Mars. While the presence of organics doesn’t prove that life existed on ancient Mars, it suggests the planet may have had the ingredients required for life.
A paper describing the detection of methane was published online on Dec. 16 in the journal Science.