Curiosity rover finds no evidence of methane on Mars

Nature : Curiosity’s Tunable Laser Spectrometer (TLS) fires a laser into a chamber that has been filled with Martian air, and scientists at the Jet Propulsion Laboratory in Pasadena, California, examine the resulting absorption lines. Based on their samples so far, they have found no evidence of methane, which deals a blow to hopes for the presence of microbial life on Mars. Methane, which exists on Earth at levels of about 1700 parts per billion, is primarily produced by living creatures. Past remote observations of Mars had detected levels of 30 parts per billion and 45 parts per billion, but the methane often appeared as localized blooms that quickly disappeared. What caused the blooms to occur and why the methane seemed to disappear instead of dispersing are both unknown. Chris Webster, head of the team running the TLS, says that Curiosity will continue taking air samples. The team will attempt to remove the carbon dioxide and then concentrate the air samples to try to increase the device’s sensitivity by a factor of 10. However, at that level, any methane detected could be the product of natural processes such as comet or meteorite impacts.