Life Has Been Found in a Low-Oxygen, Super-Salty, Sub-Zero Arctic Spring

Once more, life has been discovered in a setting that would be extremely hostile to the majority of Earth's inhabitants.

The subzero, saline, almost oxygen-free seas are fed by water that travels through 600 meters (1,970 ft) of permafrost. Lost Hammer One of the toughest regions on Earth in the springtime is the Canadian Arctic. But life goes on even in this place.

Microbes have been discovered to be thriving in the salty water that seeps up from beneath the permafrost, and they may provide a clue to any alien microbial life that may exist on Europa, Enceladus, or Mars.

Finding life in alien conditions will be difficult. One of our greatest chances, according to scientists, may be conditions that overlap as little as possible with those on planets that are most likely to support life.

Ocean worlds like Jupiter's moon Europa and Saturn's moon Enceladus may not seem to have much in common with a desert world like Mars, but there are some characteristics we can hazard a pretty decent guess at.

Europa and Enceladus' ice shells may be hiding incredibly frigid, salty oceans, according to evidence. Perhaps there are salty lakes that are liquid and trapped beneath the surface of Mars. Probably salty to a high degree are these surroundings. They're probably below zero too because salts diminish water's freezing point. They may also have very little oxygen, which is a distinct possibility.

Recent discoveries by scientists suggest that hypersaline lakes may exist beneath Mars' southern polar ice sheet. If there are lakes there — which is still up for debate — Lost Hammer Spring is quite close to what we imagine they could look like.

Water leaks to the surface from deep inside the permafrost at temperatures about minus 5 degrees Celsius (23 degrees Fahrenheit), with less than one part per million of dissolved oxygen, approximately 24 percent salinity. Try to imagine attempting to live there. Without a lot of assistance, you couldn't.

Microbes, however, have been discovered to exist in some fairly bizarre locations. Microbiologist Elisse Magnuson of McGill University in Canada and her coworkers sought to determine if Lost Hammer Spring would be one of them given its resemblance to the maybe-lakes on Mars. It wasn't simple, though.

Lost Hammer Spring. (Elisse Magnuson)

"It took a couple of years of working with the sediment before we were able to successfully detect active microbial communities," Magnuson said.

"The saltiness of the environment interferes with both the extraction and the sequencing of the microbes, so when we were able to find evidence of active microbial communities, it was a very satisfying experience." 

The microbial community's general characterization came next. In order to do this, the scientists analyzed fragments of genetic material from their samples and divided them into dozens of bacteria from several recognized microbial phyla.

They discovered a majority of microorganisms that were totally novel to science and had particular adaptations that allowed them to not only survive but thrive in an environment like Lost Hammer Spring.

"The microbes we found and described at Lost Hammer Spring are surprising, because, unlike other microorganisms, they don't depend on organic material or oxygen to live," according to scientist Lyle Whyte of McGill University.

"Instead, they survive by eating and breathing simple inorganic compounds such as methane, sulfides, sulfate, carbon monoxide and carbon dioxide, all of which are found on Mars."

"They can also fix carbon dioxide and nitrogen gasses from the atmosphere, all of which makes them highly adapted to both surviving and thriving in very extreme environments on Earth and beyond."

Only microbial creatures, at least on Earth, have this type of metabolism, which is referred to as chemolithotrophic, and they often live in rather harsh settings. Therefore, based on what we know about both Earth and Mars, if there is life on Mars with a comparable survival strategy, it is probably very little indeed.

To understand more about how these microbes evolved to survive in such a hostile environment, the team intends to culture and analyze some of the most active members of the microbial community. According to the researchers, this knowledge may improve our comprehension of the chance that such species may appear on planets like Mars.

Which leaves just one burning question: Who is the poor unfortunate who dropped his hammer 600 meters into the permafrost of the Arctic?

The team's research has been published in The ISME Journal.