Methane doesn't last long in the atmosphere, so any detection of the gas needs to be done quite quickly after it is released.
In addition to confirming the presence of methane, the planetary scientists ran computer models to try to figure out its source, dividing the region around the Gale Crater into 30 250x250 km2 grids.
A second European spacecraft, the ExoMars Trace Gas Orbiter, is expected to shed more light on the mystery of Martian methane.
Despite the fact that much of Earth's methane is produced biologically, biological sources for Mars' methane were always unlikely.
The molecule attracts such attention because on Earth methane is generated by living organisms, as well as geological processes. The European Space Agency's Mars Express mission also caught the spike in methane levels on that date in 2013, proving that it wasn't a sensor malfunction or a mistaken reading by Curiosity.
Finding methane on Mars could indicate a microbial life.More news: NCAA Tournament Odds: Michigan State Heads into Final Four as Best Bet
More news: Arsenal midfielder Aaron Ramsey's groin injury not thought to be serious
More news: Emmanuel Macron: EU cannot be ‘held hostage’ to Brexit crisis
Now an global team of experts have compared observations from two separate spacecraft, taken just one day apart in 2013, to find independent proof of methane on our neighboring planet.
It's difficulty to detect constantly suggests the methane is being released in intermittent spikes.
"In general we did not detect any methane, aside from one definite detection of about 15 parts per billion by volume of methane in the atmosphere, which turned out to be a day after Curiosity reported a spike of about six parts per billion", says Giuranna.
While the Curiosity rover measured a methane concentration of 5.78 parts per billion (ppb) in the Gale crater on June 16, 2013 the PFS recorded 15.5 ppb in the column of atmosphere above the crater, the report said. And the presence of methane was confirmed after 24 hours by NASA's Curiosity rover. Scientists estimate periodic melting causes the ice to release the compound in gas form.
In a study published Monday in the journal Nature Geoscience, the scientists present their theory: that the "geological faults" in the Aeolis Mensae region could have broken permafrost nearby and released methane that may have been trapped within it. "Let's just say it will make for an interesting discussion in the community as we seek to resolve the observations from existing and new measurements of methane on Mars".
Using numerical modeling and geological analysis, they also propose that the methane is released in a region of geological faults, pinpointing a promising location for future investigations into the origin of methane on Mars.
The ESA-Roscosmos ExoMars Trace Gas Orbiter, which is created to make the most detailed inventory of the martian atmosphere yet, began its science observations in April 2018.