Two super salty lakes hidden deep beneath Canadian glaciers may give scientists terrestrial models of the moons, which may be our best shot at finding extraterrestrial life in the solar system.
There are plenty of lakes hidden below glaciers—about 400 around the world—but scientists believe most of them are freshwater, just like most lakes above the surface. That's what makes the two newly identified lakes so intriguing, according to a recent paper published in the journal Science Advances.
"I was not looking for the subglacial lakes specifically, because I didn't expect them to be there," lead author Anja Rutishauser, a doctoral student at the University of Alberta, told the Canadian Broadcasting Corporation. "I did the analysis multiple times, because I was, like, 'Can I really trust this?'"
The reason why Rutihauser was so surprised to find lakes was that it's far colder below these glaciers than should be possible for water to remain liquid—just below 0 degrees Fahrenheit, or about 30 degrees colder than water usually freezes.
That icy temperature is also what pointed to the most unusual feature of these two lakes: they must be incredibly salty, since salt reduces the freezing point of water, keeping it liquid at colder temperatures at which pure water would turn to ice. That's why people spread salt on a sidewalk during a winter storm.
The team thinks all that salt—about four times more than is found in seawater—may come from the bedrock beneath the lakes. While the scientists haven't sampled that rock directly, geological work has found salt layers in nearby areas. They also confirmed that the lakes aren't connected to other bodies of water, having been cut off for about 120,000 years.
They hope in the long run to sample the lakes directly, particularly to see whether anything is living in them. That's a challenging prospect, since it will require extremely clean equipment to avoid contaminating the lakes and confusing the data. But if that work is successful, these lakes would join other extreme places on Earth where scientists look for simple organisms in order to better understand the potential for life elsewhere in the solar system.
In particular, conditions in the lakes could resemble Jupiter's moon Europa and Saturn's moon Enceladus, both of which hide giant salty oceans beneath shells of ice. Scientists are planning to gather more data about Europa with a mission due to launch in the 2020s, but the Canadian Arctic, as challenging a destination as it can be, is much easier to study.
