Summary: Detection of Methane in the
Atmosphere of Mars
* Sushil Atreya,2
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 T 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
Methane (CH4) is an important tracer of
possible biological, internal, or atmospheric
processes on Mars. The possibility of methane-
producing bacteria or microorganisms on
Mars has been suggested in the past (1, 2).
The source of methane could also be in