Proof that Mars once harbored alien life keeps on mounting.

Weeks after NASA’s Curiosity wanderer spotted spikes of methane in the Martian environment -conceivable confirmation of biological activity -a famous geo-biologist says she sees possible indications of past life in photographs of the Martian land taken by the wanderer.

“We can spot sedimentary structures in rocks on Mars utilizing the wanderer pictures,” Dr. Nora Noffke, a associate professor at Old Dominion University in Norfolk, Va., told The Huffington Post in an email. “The structures I depict fit in with a group of microbial structures that shape by the cooperation of benthic (living on the ground) organisms with dregs dynamics (erosion) in clastic deposits, for example, sand.”

As such, if such structures do exist on Mars that recommends the planet may have once harbored microbial life. The organisms would have existed on Mars about 3.7 billion years back, Noffke said.

For her study, Noffke examined the structures seen in rocks on Mars and contrasted them with biological structures on Earth that are shaped by microorganisms living in groups called microbial mats.

“Mats are made of trillions and trillions of microorganisms that pile up on the floor of lakes, streams, seas,” Noffke said in the email. “The microorganisms communicate with one another; they pose into a thick layer and team up in picking up nutrients and light.”

In the research, Noffke outlined the similarities found between the structures on Earth and Mars:

“The microbially induced sedimentary-like structures (MISS) spotted in Curiosity wanderer mission pictures don’t have a haphazard distribution. Instead, they were discovered to be arranged in spatial affiliations and fleeting sequences that demonstrate they changed eventually. On Earth, if such MISS happened with this kind of spatial affiliation and fleeting sequence, they would be considered as having recorded the growth of a microbially commanded environment that flourished in pools that later dried totally.”