NASA reported yesterday that the Curiosity rover has not found high levels of methane in the Martian atmosphere, dashing hopes of what was expected to be another strong indication of life on Mars.
Scientists were hopeful that Curiosity would find high levels of methane in the Martian atmosphere. Excitement for the possibility was raised in 2003 when scientists reported finding plumes of methane rising over Mars. One source of methane is microbes, and scientists hoped a confirmation of higher levels of the gas would be a strong indication that living microbes were present.
The new findings do not dash all hopes that life exists on Mars. The Curiosity rover tweeted, “Lack of methane doesn’t mean Mars never supported life. Plenty of Earth organisms don’t produce the gas.”
Lack of methane doesn’t mean Mars never supported life. Plenty of Earth organisms don’t produce the gas.
— Curiosity Rover (@MarsCuriosity) September 19, 2013
President of the Mars Society Robert Zubrin also showed an optimistic view of the lack of methane on Mars, telling the New York Times:
If it had found methane, that would have been killer…Yes, it’s disappointing in that we didn’t get a pony for Christmas. But it doesn’t mean there aren’t ponies out there.
Other scientists note that if life were more abundant in the past, the methane that would have been generated then is long gone. So the hope of finding evidence of life in the past is also still possible.
The search continues, and Seth Shostak with the Search for Extraterrestrial intelligence (SETI) Institute reminds people that Curiosity is up there for a reason, and it isn’t looking at rocks. “That’s the mythology,” says Shostak. “Mars is about life, not geology, as interesting as that is. That’s the triumph of hope over measurement, and maybe it is.”