While NASA’s next Mars rover is all about finding signs of past microbial life on the surface of the red planet, a new study suggests that life on Mars may be possible in the present.
Published yesterday in the journal Nature Geoscience, the paper argues that Mars could be teeming with microbial life as we speak — and that the best place to look for it is underground.
The research was carried out by NASA scientists from Caltech and the Jet Propulsion Laboratory (JPL) in Pasadena, California, and brings evidence that Mars may have enough oxygen beneath its dry, barren surface to possibly accommodate life.
The scientists base their theory on two important recent discoveries — the heavily-oxidized Martian rocks found by the Curiosity rover two years ago and the underground liquid water lake detected earlier this year at the planet’s south pole.
On one hand, the Curiosity find hinted that Mars was once abundant in oxygen — a key ingredient for life uncovered in Mangan-rich rocks. According to the 2016 study that announced the discovery in the journal Geophysical Research Letters, the oxygen would have been present both “within the atmosphere and some groundwaters of ancient Mars.”
On the other hand, the second (and more recent) finding led researchers to speculate that some of the oxygen which once flowed on Mars could still be trapped within the vast underground lake.
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As the Inquisitr previously reported, the subsurface lake — a 12.4-mile-long body of water hidden a mile below the Martian ice cap — is the first known body of liquid water to ever be confirmed on the red planet.
Given that the Curiosity rover also stumbled upon perchlorate salts spread across the Martian landscape, scientists have reasons to suspect that this sub-glacial lake could be rich in salt.
If this is true, then — under the right circumstances — the underground pool of briny water could absorb sufficient molecular oxygen from the Martian atmosphere to sustain simple microorganisms, explains Caltech.
“If salty water were close enough to the surface of the Martian soil, then it could effectively absorb oxygen from the thin atmosphere.”
“We found something very surprising: many brines can exist in different places on Mars,” lead study author Vlada Stamenkovic told Popular Mechanics. “They fully suffice to allow the aerobic breathing for microbes and even sponges, which are the simplest animals.”
#Space : Sponges from Mars? Study suggests water on the red planet could support life. Brine deposits below the surface of Mars, particularly near the poles, can contain molecular oxygen – https://t.co/dKBkmYA8jq pic.twitter.com/qlLgcBWuBy
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This hypothesis “challenges traditional beliefs about the planet’s habitability,” notes Caltech, by showing that Mars could actually have more oxygen than previously believed — or, at least, sufficient amounts to foster some level of subsurface life.
“Nobody ever thought that the concentrations of dissolved oxygen needed for aerobic respiration could theoretically exist on Mars,” said Stamenkovic, who is a planetary scientist and theoretical physicist at NASA’s JPL.
To test out their supposition, the researchers devised a chemical experiment meant to calculate how much atmospheric oxygen can be absorbed by salty water. The results revealed that the subsurface reservoir of briny water on Mars could hold “an unexpectedly high amount of oxygen” — in fact, a lot more than is required “for aerobic respiration in Earth’s oceans today.”
According to Caltech, the oxygen stores on Mars would be created specifically “at low-enough elevations (where the atmosphere is thickest) and at low-enough temperatures (where gases like oxygen have an easier time staying in a liquid solution).”
“Our findings suggest that there can be near-surface environments on Mars with sufficient oxygen available for aerobic microbes to breathe,” the authors wrote in their paper, noting that “aerobic life may exist on modern Mars and on other planetary bodies” that harbor subsurface sources of oxygen.
This is not the first time that scientists have speculated on the prospect of subsurface microbial life on Mars. Last month, an article published in The Conversation debated the potential life forms that could inhabit the Martian underground salty lake, as the Inquisitr reported at the time.