Detection of Methane in the Atmosphere of Mars
Encrenaz, Thérèse; Formisano, Vittorio; Giuranna, Marco; Atreya, Sushil; Ignatiev, Nikolai
Italy, United States, France, Russia
Abstract
We report a detection of methane in the martian atmosphere by the Planetary Fourier Spectrometer onboard the Mars Express spacecraft. The global average methane mixing ratio is found to be 10 +/- 5 parts per billion by volume (ppbv). However, the mixing ratio varies between 0 and 30 ppbv over the planet. The source of methane could be either biogenic or nonbiogenic, including past or present subsurface microorganisms, hydrothermal activity, or cometary impacts.