Curiosity Detects Unusually High Methane Levels
This week, NASA’s Curiosity Mars rover found a surprising result: the largest amount of methane ever measured during the mission — about 21 parts per billion units by volume (ppbv). One ppbv means that if you take a volume of air on Mars, one billionth of the volume of air is methane.
The finding came from the rover’s Sample Analysis at Mars (SAM) tunable laser spectrometer. It’s exciting because microbial life is an important source of methane on Earth, but methane can also be created through interactions between rocks and water.
Curiosity doesn’t have instruments that can definitively say what the source of the methane is, or even if it’s coming from a local source within Gale Crater or elsewhere on the planet.
“With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern,” said SAM Principal Investigator Paul Mahaffy of NASA’s Goddard Spaceflight Center in Greenbelt, Maryland.
The Curiosity team has detected methane many times over the course of the mission. Previous papers have documented how background levels of the gas seem to rise and fall seasonally. They’ve also noted sudden spikes of methane, but the science team knows very little about how long these transient plumes last or why they’re different from the seasonal patterns.
Click here to read the full press release from NASA.
Curiosity features in Issue 2 of the Astrobiology Graphic History series, available at: https://astrobiology.nasa.gov/resources/graphic-histories/
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