Evidence for intense local enhancements in methane on Mars has been bolstered by ground-based observations. The methane, as well as water on Mars, was detected using state-of-the-art infrared spectrometers stationed atop Mauna Kea, Hawaii and in Cerro Pachón, Chile.
Scientific teams around the globe are on the trail of methane seeping out of Mars. And for good reason: The methane could be the result of biological processes. It could also be an "abiotic" geochemical process, however, or the result of volcanic or hydrothermal activity on the red planet.
http://www.space.com/scienceastronomy/050419_mars_methane.html
