Once again, life has been found in an environment that would be deeply inhospitable to most organisms living on this planet.
Powered by water flowing through 600 meters (1,970 feet) of permafrost, the sub-zero, salty, virtually oxygen-free hammer source lost in the Canadian Arctic is one of the hardest places on Earth. Even here, however, life finds a way.
Scientists have found microbes thriving in salt water that seeps from the depths below the permafrost, and could provide a clue to extraterrestrial microbial life that could be found (if any) in Europe, Enceladus or Mart.
Life in extraterrestrial environments will be hard to find. Scientists think that one of our best bets could be environments that intersect as much as possible with those of the worlds most likely to host life.
Oceanic worlds like Jupiter’s Europa Moon and Saturn’s Enceladus Moon may not have much in common with a desert world like Mars, but there are some features about which we can risk a pretty decent guess.
Evidence suggests that the extremely cold and salty oceans could hide under the ice shells of Europe and Enceladus. Mars could also have liquid salt lakes enclosed beneath its surface. These environments are probably hypersaline. As the salts lower the freezing point of the water, they are likely to be below zero as well. And it is more than possible that they are extremely low in oxygen.
Not long ago, scientists found evidence that there could be hypersaline lakes under the southern polar ice sheet of Mars. While this discovery is still a hotly debated topic, if there are lakes, Lost Hammer Spring is pretty close to what we think they might be.
From the depths below the permafrost, water with less than one part per million dissolved oxygen, about 24 percent salinity, and temperatures around 5 degrees Celsius (23 degrees Fahrenheit) seeps into the surface. Imagine trying to live in that. You couldn’t, not without significant help.
But microbes have been found living in some pretty crazy places. Given its similarity to the perhaps lakes of Mars, microbiologist Elisse Magnuson of McGill University in Canada and her colleagues wanted to see if Lost Hammer Spring could be one of them. Although it was not easy.
Lost hammer jump. (Elisse Magnuson)
“It took a couple of years of working with the sediment before we could successfully detect active microbial communities,” Magnuson explained.
“The salinity of the environment interferes with both the extraction and sequencing of microbes, so when we were able to find evidence of active microbial communities, it was a very satisfying experience.”
The next step was to roughly characterize the microbial community. To do this, the team sequenced scraps of genetic material found in their samples, classifying them into dozens of microbes belonging to several known microbial threads.
Most of the microbes they found were completely new to science and had specific adaptations to allow them to not only live, but also thrive, in a place like Lost Hammer Spring.
“The microbes we found and described in Lost Hammer Spring are amazing, because, unlike other microorganisms, they don’t depend on organic matter or oxygen to live,” said microbiologist 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 gases from the atmosphere, which makes them highly adapted both to survive and to thrive in very extreme environments on Earth and beyond.”
This type of metabolism is known as chemolithotrophic and has only been found in microbial organisms, at least here on Earth, and usually in fairly extreme environments. Therefore, if there is life on Mars with a similar survival strategy, it is likely that, as far as we know from both Earth and Mars, it is very small.
The team plans to cultivate and study some of the most active members of the microbial community to try to learn more about how they adapted to thrive in such an inhospitable environment. This information could help us better understand the likelihood of these organisms arising in places like Mars, the researchers said.
Which leaves only one hot question: who is the poor blue man who lost his hammer 600 meters below the Arctic permafrost?
The team’s research has been published in The ISME Journal.