Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Astrochemistry

Methane burst detected on Mars

Curiosity rover reports highest concentration yet

by Sam Lemonick
June 29, 2019 | A version of this story appeared in Volume 97, Issue 26

 

Photograph of rocks taken by Mars rover Curiosity.
Credit: NASA/JPL-Caltech
Mars rover Curiosity detected a transient spike of methane gas at Teal Ridge, pictured here.

Last week, NASA scientists reported that the Curiosity rover had detected methane levels higher than any previously seen on Mars’s surface. The signal returned to background levels within days. Various missions dating back to 2003 have reported methane on Mars, typically less than 1 ppb at the planet’s surface, with seasonal variations (Science 2018, DOI: 10.1126/science.aaq0131). The 21 ppb detected this month is about three times as high as a previous spike the rover observed starting in late 2013 (Science 2015, DOI: 10.1126/science.1261713). On Earth, methane is often produced by microbes or by geochemical processes that happen when water interacts with certain minerals at high pressure. NASA scientists say Curiosity does not have the instruments to determine the origin of the gas, and they are waiting for two European Mars orbiters to corroborate the spike. Fred Goesmann of the Max Planck Institute for Solar System Research thinks the recent measurements are probably accurate and says the methane emission is a mystery. “If we see such a high concentration and it’s gone the next day, then it’s a really interesting story. Where does it come from and how?” He doesn’t think this recent spike is related to seasonal effects, and he points out that biological processes would produce constant emissions, not bursts. He’d like to see continuous surface measurements to find how quickly the gas comes and goes, but current rovers can’t do this.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.