1st Methane, Now Oxygen: Another Possible ‘Biosignature’ Gas Is Acting Weird on Mars On November 14, 2019 By peanutgallerynhIn Science and Stuff, 1st Methane, Now Oxygen: Another Possible ‘Biosignature’ Gas Is Acting Weird on Mars | Space Wild. Share this: Share on X (Opens in new window) X Share on Reddit (Opens in new window) Reddit Share on Facebook (Opens in new window) Facebook Like Loading... Related