Curiosity: Negative results of Methane
Data received from Curiosity has revealed the Martian environment lacks methane.
This is a surprise because previous data reported by scientists and various observations indicated positive detections of this gas. The roving laboratory performed extensive tests to search for traces of Martian methane. Whether the Martian atmosphere contains traces of the gas has been a question of high interest for years because methane could be a potential sign of life, although it also can be produced without biology.
Methane in the Martian atmosphere was also detected in the past by sensors of orbital probes. Its existence was confirmed also by data received from the European orbiter of the red planet – Mars Express. Also, some previous spectrographic measurements with the use of telescopes on Earth had confirmed that Methane is present in the Martian atmosphere.
Methane could be evidence of microbial life forms on Mars as its presence could be the result of life or volcanic activity. There has not been any volcanic activity detected on Mars, so searching for this gas is one of the targets of more measurements.