New readings from NASA's Curiosity rover received on Friday again detected methane but at much higher concentrations than earlier reported, according to The New York Times. The newest measurements are 21 parts per billion.
So why is this unusually large amount of methane so interesting?
But although the robot's big onboard chemistry lab - the Sample Analysis at Mars (SAM) instrument - can detect the gas's presence, it can say nothing about the source.
Sadly, Curiosity doesn't have the right instruments needed to definitively determine the source of the methane, or pinpoint whether it's coming from a local source within Gale Crater or somewhere else on the planet, altogether.
A new image captured by NASA's Mars Curiosity rover shows something that, at the moment, remains unexplained: a bright flash popping up, seemingly out of nowhere, and with no indication of what may have caused it. The research team has also noted sudden spikes of methane in the past, but very little is known about how long these transient plumes last or why they're different from the seasonal patterns.
Both Curiosity and ESA's Mars Express probe have previously measured methane spikes on Mars. "Curiosity will likely continue to make measurements, and it will be interesting to see whether they still see the methane, or whether it disappears immediately".
They will also reach out to other science teams.
"Combining observations from the surface and from orbit could help scientists locate sources of the gas on the planet and understand how long it lasts in the Martian atmosphere", NASA officials said in the same statement. The rover also detected methane in the Martian atmosphere. The compound isn't exactly rare in the Solar System, yet as far as we know, only Earth's is a product of biological processes.
The source of methane can be one of two things.
No matter its goal, these work as "chemical clues" for researchers studying Mars. "The previous "discrepancy" in findings was always complicated by the fact that we never made measurements at the same time", Patel said.
The rover's laser spectrometer device detected the methane while the car-size rover was parked at the Teal Ridge site within Gale Crater, a 96-mile-wide dry lake bed that was created millions of years ago by an asteroid impact. The Methane gas detected might simply be the ancient gas captured in the planet.