Mars mystery: Rover finds methane, but what is producing the gas?

Depiction of NASA rover on surface of Mars

Image: NASA

New findings from the Mars rover Curiosity have revealed that there are trace amounts of methane gas on Mars, according to a study by a team of NASA scientists that includes a Texas A&M University researcher.

Mark Lemmon, associate professor of atmospheric sciences at Texas A&M, who has served as a camera operator on numerous Mars missions, especially those involving the Mars rovers Spirit, Opportunity and Curiosity.  He is part of a team of international researchers led by Chris Webster at NASA’s Jet Propulsion Laboratory that have had their work published in the current issue of Science Express.

Numerous previous studies had concluded that methane was not likely to be abundant on Mars, until observations from Earth and space suggested surprisingly high quantities. While Curiosity’s early measurements did not clearly detect methane, the new study shows measureable amounts of methane and definite variability.

The findings add to the body of knowledge known about Mars’ complex atmosphere. Scientists have previously proven that Mars has numerous gases, among them carbon dioxide (which makes up about 95 percent of its atmosphere), argon, nitrogen, oxygen and carbon monoxide.

“The mysterious thing about methane on Mars is that we don’t really know where it comes from,” Lemmon explains.

“It seems to change over time, so we think the methane may be seasonal or episodic. While trace amounts of methane have been expected, the detections show there is sometimes a surprisingly large amount.”

The presence of methane has been of keen interest because it could indicate the possibility of life on Mars, although methane is able to form without the presence of life.

Lemmon says the team is not sure where the source of the methane originates.  It could be a result of geothermal activity on the planet or from another source.

Curiosity landed in Gale Crater on Mars in August of 2012 and has performed dozens of experiments while it slowly travels around the crater.

The project was funded through NASA and its Jet Propulsion Laboratory in Pasadena, Calif.

For more about the project, go to

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