Gale Crater hosted life on Mars? NASA's Curiosity reveals a lake could have hosted wide variety of microbial life

Based on the data revealed by NASA’s Mars Curiosity rover, scientists have claimed that the Gale Crater on Mars had the right physical and chemical conditions for life for 700 million years. They have also claimed that during that period, it also had a lake that could have hosted a wide variety of microbial life.

The new findings have found space in the journal Science. The report shows a long-lasting Martian environment having the potential to host a wide variety of living things during that period.

“It helps to broaden our understanding of what it meant to be a habitable environment on Mars, 31⁄2 billion years ago,” said lead author Joel Hurowitz, a geochemist at Stony Brook University.

The NASA Mars Curiosity rover reached Gale Crater in 2012 and since then it has drilled, X-rayed and laser-blasted a variety of rocks in order to find out whether Mars could have conditions to support life. 

NASA Mars Curiosity rover with its instruments was on a mission to drive to Mount Sharp, the 3-mile-high mound in the middle of the crater. It would climb its slopes, studying each sedimentary layer of rock like a chapter in the geologic history of Mars.

Curiosity had also discovered evidence of water on Mars as well as the right chemical ingredients required for life. According to recent studies, Gale Crater was once home to a series of lakes that may have risen and fallen over time.

Scientists have now brought together the evidence from several spots that fall to and up Mount Sharp and include six drilled rock samples pulled from very different ancient environments. As a result, a wealth of life supporting ingredients such as carbon compounds, nitrogen, and phosphate minerals, as well as iron and sulfur minerals in different redox states were found.

“Our analysis of those rocks indicates that gradients in lakewater oxidation state were present in the primary lacustrine environment,” the study authors wrote. “Taken together, these results provide compelling evidence that the physical, chemical and energetic conditions necessary to establish a habitable environment were present on Mars between 3.8 and 3.1 (billion years ago).”

Also, a strange pattern in a stretch of layered rock was seen. Some regions had lots of coarse sediment being rapidly dumped, making the shallows where water flowing into the lake from a stream or river would have dropped much of its heavy material. 
Also some areas had much finer-grained sediment been layered on more gradually — closer to the middle of the lake, and farther away from the river mouth.

It appears that the minerals present in the shallower parts of the lake were more exposed to oxygen in contrast to the minerals in the deeper areas.

Apparently, the waters in Gale Crater’s lake had differentiated into an oxygen-rich layer near the surface, and an oxygen-poor layer in its depths. That’s quite similar to like lakes on Earth, which differentiate in the same way.

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“It’s that relationship between the mineralogy and the thickness of the sediment layers that allows us to connect the dots,” said study co-author Ashwin Vasavada, the mission’s project scientist at Jet Propulsion Laboratory.

Hurowitz said this complex lake could have lasted from hundreds of thousands of years to 10 million years. Like the lakes on Earth, the one in Gale Crater could have hosted a variety of microorganisms.

ALSO READ | NASA Curiosity Rover mission: Ancient lake on Mars may have offered suitable environment to microbial life