It's often been said that where there's water there's life, but NASA now looks to be seeing if the same can also be said of good 'ol methane, with New Scientist reporting that researchers at the agency have drawn up plans for a rocket plane that could one day sniff out sources of the gas on Mars. If it's given the go ahead, the plane would parachute down to Mars before being cut loose at an altitude of 1.5 kilometers, when the plane's rockets would kick it send it skimming across the Martian surface. On board sensors would then be able to detect methane at levels as low as a few parts per billion, as well as determine the source of the gas, which some speculate could be living micro-organisms. Of course, there's no indication of when that might take place, with the plane already failing to make the shortlist for NASA's 2011 Mars Scout mission.