Click For Photo: https://cdn.mos.cms.futurecdn.net/8qFxCaGd2Qv5iHCnjEFrhM-1200-80.jpg
SAN FRANCISCO — NASA's Curiosity rover may have just taken a big step toward cracking at least part of the Mars methane mystery.
Curiosity's measurements show that methane levels cycle seasonally inside the Red Planet's 96-mile-wide (154 kilometers) Gale Crater, which the rover has been exploring since August 2012. The six-wheeled robot has also detected several big surges of the gas, which is a possible (though far from definitive) sign of Mars life.
Mystery - View - Above - Trace - Gas
But here's where the mystery comes in: The view from above is very different. The European-Russian Trace Gas Orbiter (TGO), which was designed to sniff out low-abundance gases such as methane, has found the Martian air to be virtually free of the stuff.
Click here for more Space.com videos...
Example - TGO - Limit - Parts - Ppb
For example, TGO recorded an upper limit of 0.012 parts per billion (ppb) methane during its first four months of full science operations, which lasted from April through August 2018. That's about 35 times lower than the background methane levels Curiosity measured inside Gale over the same period.
The discrepancy between ground measurements and orbital data has the Curiosity team "mystified, just like everyone else," mission principal investigator Ashwin Vasavada said here last week during a media roundtable at the annual fall meeting of the American Geophysical Union (AGU).
Something - Martian - Atmosphere - Gas - Curiosity
Perhaps something in the Martian atmosphere destroys methane very quickly, scrubbing away most of the gas that rises above Curiosity and therefore leaving little for TGO or Mars Express to detect, said Vasavada, who's based at NASA's Jet Propulsion Laboratory in Pasadena, California. But that's not the only possible explanation.
"Maybe the expansion and contraction of the atmosphere every day from solar heating is responsible," he told Space.com after the roundtable.
Curiosity - Methane - Measurements - Rover - Analysis
Curiosity's previous methane measurements — which the rover makes using its Sample Analysis at Mars instrument, or SAM — have been gathered...
Wake Up To Breaking News!
Never argue with an idiot, the spectators may not be able to differentiate between you.