Mars rover Curiosity was sent to Mars with a primary mission to discover if the red planet’s environment was ever suitable for life as we known it. As part of that mission, the rover has been analyzing Martian materials, searching for methane – a hydrocarbon that could be a sign of life. Initial chemical analyses on Mars soil samples failed to find any Methane, and the rover moved on to testing the planet’s atmosphere.

From October 2012 to this summer (on Earth), Curiosity analyzed the Martian atmosphere on six separate occasions. Today, NASA definitively stated that Curiosity’s Tunable Laser Spectrometer has failed to find significant concentrations of methane in the Martian atmosphere. The agency estimates there is less than 1.3 parts per billion of Methane in Mars’ atmosphere. This conflicts with previous research that had found evidence for the compound on Mars, estimating up to 45 parts per billion in the planet’s atmosphere.

“It would have been exciting to find methane, but we have high confidence in our measurements, and the progress in expanding knowledge is what’s really important,” said Chris Webster, lead author of a paper on the findings published today in the journal Science Express. “We measured repeatedly from Martian spring to late summer, but with no detection of methane.”

Methane can sometimes be a by-product of biological processes, which is why high estimates of methane on Mars excited researchers. Curiosity’s findings could be seen as a disappointment, but Mars researchers are trying their best not to be dour.

“This important result will help direct our efforts to examine the possibility of life on Mars,” said Michael Meyer, lead scientist for Mars exploration at NASA. “It reduces the probability of current methane-producing Martian microbes, but this addresses only one type of microbial metabolism. As we know, there are many types of terrestrial microbes that don’t generate methane.”

(Image courtesy NASA)