Scientists have confirmed in Nature Geoscience on Monday that methane gas was detected on Mars inside the 96-mile-wide depression near the Martian equator known as Gale Crater. The intrigue surrounding the presence of methane—a gas emitted by living creatures on Earth—could suggest that there are signs of life on the Red Planet.

We may be one step closer to cracking the Mars methane mystery. https://t.co/BxNYr2PL1c — Scientific American (@sciam) April 2, 2019

The location of these emissions are believed to be just below the surface east of Gale Crater, which was found by NASA’s Curiosity rover that has been exploring the region since 2011. The source of methane has been pared down to a few likely scenarios, which include serpentinization or the actual existence of microorganisms that have been releasing the gas into the atmosphere.

"Methane is important because it could be an indicator of microbial life," Marco Giuranna of Rome's National Astrophysics Institute said, per Phys.org. "But life is not required to explain these detections because methane can be produced by abiotic processes."

"Though not a direct biosignature of life, methane can add to the habitability of martian settings, as certain types of microbes can use methane as a source of carbon and energy," Giuranna added.

About a decade and a half ago, three teams of scientists claim to have detected methane in the Martian atmosphere, but in 2017, the methane had disappeared, the New York Times reports. This finding suggests that something on the Red Planet is responsible for producing the gas in small, episodic emissions, however, it cannot be confirmed just yet. These questions will undoubtedly spark further research into the methane's existence.