Planetary scientists have been puzzling over what could be producing methane gas detected in Mars thin atmosphere. Methane molecules are easily blown apart by ultraviolet light from the Sun, so any methane around must have been released recently. The presence of methane has triggered a hot debate in the Mars science community: is it a sign of microbial life or geology?
The answer might come from the launch tomorrow of NASA’s Mars Science Laboratory rover, called Curiosity, scheduled to land on Mars in August 2012, carrying with it the Sample Analysis at Mars (SAM) suite, which will measure a multitude of trace constituents and isotopes from gas and solid samples. Two of the SAM instruments, the tunable laser spectrometer and the quadrupole mass spectrometer, could potentially detect a whiff of methane – at the 1 part per billion level or lower – in the air around the rover landing site at Gale Crater.
“Based on evidence, what we do have is, unequivocally, the conditions for the emergence of life were present on Mars — period, end of story,” said Michael J. Mumma, a senior scientist for NASA at the Goddard Space Flight Center in Greenbelt, Md., who led one of three teams that have made still-controversial claims of detecting methane in Mars’s atmosphere. “So life certainly could have arisen there.”
Observations over the last decade suggest that methane clouds form briefly over Mars during the summer months. The discovery has left many scientists scratching their heads, since it doesn’t fit into models of the martian atmosphere. The image above shows a map of methane concentrations in Autumn (first martian year observed) overlayed on true colour map of Mars.