a clue for Mars? – OI Canadian

No oxygen, negative temperatures and a lot of salt: this is an unlivable environment. However, microorganisms have been found there. This research is important for understanding life on Earth… and potentially on Mars.

Welcome to the Lost Hammer Water Source on Axel Heiberg Island in the Canadian Arctic. In this underground, there are freezing temperatures below zero. At such temperatures, water is supposed to freeze. But this one is so salty that it is not. It also contains no oxygen (or such a tiny level that it cannot be consumed). Lost Hammer Spring is therefore an icy spring, but liquid, as much as excessively salty and unbreathable. Life in such a place would be extremely unlikely. Except that life can surprise.

Scientists have spotted bubbles of methane rising to the surface. This phenomenon can be of geological as well as biological origin. It is to this enigma that a field study has tried to answer, from sediments collected on site. Initially published in April 2022, it was commented on by its authors at the end of June 2022 on the McGill University website (at the origin of this research).

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The Lost Hammer Spring // Source: McGill University / Elisse Magnuson

It turns out that the methane bubbles did have a biological and therefore living source: anaerobic organisms (not requiring oxygen), which essentially feed on methane and breathe sulphate instead of oxygen. ” It took us two years of sediment work before we were able to detect active microbial communities “, says Elisse Magnuson, doctoral student at McGill University and lead author of the study. Because the salinity of the environment interferes with the extraction and sequencing of microbes.

Could life on Mars look like this?

The discovery is surprising, because the microorganisms of Lost Hammer ” do not depend on organic matter or oxygen to live “says Lyle Whyte, the team leader. Instead, they survive on inorganic compounds — methane, sulphides, sulphates, carbon monoxide, carbon dioxide. “ They can also fix carbon dioxide and nitrogen gas from the surrounding atmosphere, making them highly suited to survive and thrive in very extreme environments on Earth and beyond. »

But why does Lyle Whyte also bring up very extreme environments? beyond ” of the earth ? It turns out that, on Mars, we find traces of the same inorganic compounds that these organisms depend on; and there is water in ice form. As a result, the European Space Agency has recovered several samples from Lost Hammer to test the capabilities of detecting organic life for its ExoMars mission (whose rover launch is temporarily on hold).

This research work shows that the origin of methane ” has no importance “says Lyle Whyte. ” If you are in a situation where you have very cold salt water, it could potentially harbor a microbial community, even in this extremely harsh environment. »

Such conclusions absolutely do not prove that there is life on Mars. They show their potential and what form these organisms could take. However, to find something, it is very useful to know roughly what to look for.

Everything you need to know about the red planet Mars

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