NASA’s Curiosity rover mission recently determined that background levels of methane in Mars’ atmosphere cycle seasonally, peaking in the northern summer. These finds have intrigued astrobiologists, because methane is a possible biosignature. The vast majority of methane in Earth’s air is pumped out by microbes and other living creatures.
Some answers may soon be on the horizon, because that June 2013 detection has just been firmed up. Europe’s Mars Express orbiter noted the spike as well from that spacecraft’s perch high above the Red Planet, a new study reports.