New evidence found that Mars has a glacier, which might hide a salty lake underneath. But now a new question arises: would something live under that frozen brine?
John E. Hallsworth, a Lecturer of Environmental Microbiology at Queen’s University (Belfast) explains in an article posted on Conversations all the possibilities and difficulties a Martian form of life would face – if discovered.
Mars was a watery planet and should have harbored some life form. If not alive now, it should at least has some fossilized evidence. Past exploration missions might have also contaminated Mars with microbes from Earth, which would now live in that lake.
Hallsworth explains that we shouldn’t expect to find something bigger than microbes in that lake. Considering the subzero temperature, the lack of food to sustain larger organism, it’s highly unlikely that we’d find insects or fish out there.
However, microorganisms might be present there, as they can inhabit hostile environments.
The author added that, according to research on Earth, many microbes could live in brine – there are “halophilic microbes” which have adapted to live in high salt levels. The halophiles on Earth are also very tolerant of UV light and low temperature, some can even breathe even if there is no oxygen.
Hallsworth concludes that:
“Certain halophilic microbes – including the fungus Aspergillus penicillioides, the bacterium Halanaerobium and methane-producing organisms known as archaea – may be able to survive in a Martian brine.”
What About the Freezing Temperatures?
These microbes might be resistant to low temperatures, but can they resist in -70ºC? Hallsworth explains that the freezers scientists use to preserve microbial cells in a viable and dormant condition would be somewhere between -70ºC and -80ºC. Also, he said that some salts in the Martian lake could make temperatures higher than -70ºC:
“It is therefore beyond doubt that some microbial systems could be preserved (and probably survive) on Mars.”
What Hallsworth would like to find out is what kind of salts the lake contains, because salt is the one that determines if there could be microbial activity or not. Moreover, Mars contains sulfate salts, which, if present in the lake, it could make it less habitable. Other salts (magnesium chloride and perchlorates) could even boost cellular metabolism, by making microbes more resistant to low temperatures.
Hallsworth concludes that as soon as the subglacial salty lake on Mars is confirmed, scientists will have to learn about the salts it contains. If there are terrestrial microbes on Mars, they could be alive and inactive, added the author:
“And once there is active life on Mars, it is logical to assume that there will also be evolution of that life taking place. A subglacial saline martian lake is, in reality, more likely to act as a preservation chamber than a cradle of life.”
This is great news, making the lake a perfect place to start searching for ancient forms of life on Mars.
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.