Scientists turn back time to track methane emissions on Mars

NASA’s Curiosity rover landed on Mars in August 2012, and its investigations revealed that Mars was once a potentially habitable planet. One of Curiosity’s most exciting observations has been periodic, unusually high abundances of methane in Mars’s atmosphere. Over the past seven years, Curiosity has established a background signal of methane of about 0.41 part per billion by volume (ppbv), and these periodic spikes can increase atmospheric methane to as much as 21 ppbv.