Gas spike on Mars a thrill for scientists
Mars, it appears, is belching a large amount of a gas that could be a sign of microbes living on the planet today.
In a measurement taken Wednesday, NASA’s Curiosity rover discovered startlingly high amounts of methane in the Martian air, a gas that on Earth is usually produced by living things. The data arrived on Earth on Thursday, and by Friday, scientists working on the mission were excitedly discussing the news, which has not yet been announced by NASA.
“Given this surprising result, we’ve reorganized the weekend to run a follow-up experiment,” Ashwin Vasavada, the project scientist for the mission, wrote to the science team in an email obtained by the New York Times.
The mission’s controllers on Earth sent new instructions to the rover Friday to follow up on the readings, bumping previously planned science work. The results of these observations are expected back on the ground Monday.
People have long been fascinated by the possibility of aliens on Mars. But NASA’s Viking landers in the 1970s photographed a desolate landscape. Two decades later, planetary scientists thought Mars might have been warmer, wetter and more habitable in its youth some 4 billion years ago. Now, they are entertaining the notion that if life ever did arise on Mars, its microbial descendants could have migrated underground and persisted.
Methane, if it is there in the thin Martian air, is significant, because sunlight and chemical reactions would break up the molecules within a few centuries. Thus any methane detected now must have been released recently.
On Earth, microbes known as methanogens thrive in places lacking oxygen, such as rocks deep underground and the digestive tracts of animals, and they release methane as a waste product. However, geothermal reactions devoid of biology can also generate methane.
It is also possible that the methane is ancient, trapped inside Mars for millions of years but escaping intermittently through cracks.
Scientists first reported detections of methane on Mars a decade and a half ago using measurements from Mars Express, an orbiting spacecraft built by the European Space Agency and still in operation, as well as from telescopes on Earth.
When Curiosity arrived on Mars in 2012, it looked for methane and found nothing, or at least less than 1 part per billion in the atmosphere. But in 2013, it detected a sudden spike, up to 7 ppb that lasted at least a couple of months.
The measurement this week found 21 ppb, or three times the 2013 spike.