quote [ This week, NASA's Curiosity Mars rover found a surprising result: the largest amount of methane ever measured during the mission - about 21 parts per billion units by volume. ... The finding came from the rover's Sample Analysis at Mars tunable laser spectrometer. It's exciting because microbial life is an important source of methane on Earth, but methane can also be created through interactions between rocks and water.

"With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern," said SAM Principal Investigator Paul Mahaffy. ]