New readings from the NASA rover Curiosity have diminished the hope that life could be found on Mars.
The rover has not found a trace of methane on the surface of the planet, which significant reduces the odds of discovering life there.
“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, NASA’s manager of Planetary Sciences Instruments. “We measured repeatedly from Martian spring to late summer, but with no detection of methane.”
NASA reports that Curiosity has been exploring the Martian surface for traces of the gas since it began its mission over a year ago. The rover has found evidence that water once flowed across the surface of the planet and that there are other trace elements that could indicate life exists or once existed on Mars.
However, without methane, scientists doubt that the Red Planet sustained life.
NASA scientists indicate that traces of methane would remain on the surface and in the atmosphere of the planet for at least 100 years.
“This important result will help direct our efforts to examine the possibility of life on Mars,” said Michael Meyer, NASA’s lead scientist for Mars exploration, in a statement. “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.”
According to NASA, Curiosity analyzed samples of the Martian atmosphere in search of methane six times between October 2012 and June 2013. Nothing was detected, leading scientists to calculate that the amount of methane must be no more than 1.3 parts per billion.
That, the space agency noted, is one-sixth of the amount that scientists had expected to find.