WIKIMEDIA, NASA/JPL-CALTECH
Two years into the Curiosity rover’s exploration of Mars, NASA researchers have unveiled several findings consistent with the idea that the planet once harbored living organisms. The scientists cautioned, however, that there is still no direct evidence of life on Mars, and inorganic processes could also account for their results.
In a paper published this week (December 16) in Science, researchers reported the detection of methane in the air at Gale Crater, where the rover previously uncovered evidence of a long-lost lake. The level of methane in the atmosphere of Mars is around one part per billion—about 4,000 times lower than the concentration found on Earth. Methane is commonly produced as metabolic waste, but can also be made by inorganic processes such as the mixing ...
