Scientists think they know what the source of methane in Mars' atmosphere could be

Since methane traces were reported in Mars’ atmosphere, a debate has raged over the findings’ accuracy. Because methane gas dissipates relatively quickly — within around 12 years on Earth — and due to the difficulty of observing Mars’ atmosphere, many scientists questioned previous studies that relied on a single data set. Furthermore, they conducted two parallel experiments to determine the most likely source of methane on Mars to be an ice sheet east of Gale Crater – itself long assumed to be a dried up lake. “Two completely independent lines of investigation pointed to the same general area of the most likely source for the methane.” Europe’s Mars Express probe measured 15.5 parts per billion in the atmosphere above the Gale Crater on June 16, 2013. Giuranna said that while methane is a sign of life on Earth, its presence on Mars doesn’t necessarily constitute evidence of something similar on the Red Planet.