On Jupiter’s moon Europa, a saltwater ocean exists deep within a thick ice cap.
Now, a surprising connection between the ice sheet and the Greenland ice sheet on Earth has provided a new perspective: Europa’s ocean may be habitable, according to a new study.
Scientists have been intrigued for more than 20 years by the dramatic breaks in Europa’s icy surface.
These double ridges have ridges that can reach almost 305 meters in height, with wide valleys between them.
These features were first photographed by NASA’s Galileo spacecraft in the 1990s, but researchers have not been able to determine how they formed.
While studying the Greenland ice sheet using ice-penetrating radar observations, a team of researchers observed a similar double-ridged feature shaped like the letter M that is like a miniature version of the one on Europa.
The impact of water on the topography of the ice sheet
Airborne instruments help researchers study Earth’s polar regions for changes in ice sheets that could have an effect on global sea level. These eyes in the sky also look for surface meltwater ponds, conduits that carry seasonal drainage, and subglacial lakes.
“We were working on something entirely different related to climate change and its impact on the surface of Greenland when we saw these little double ridges, and we could see the ridges go from ‘unformed’ to ‘formed,'” the study said. lead author Dustin Schroeder, an associate professor of geophysics in the School of Earth, Energy, and Environmental Sciences at Stanford University, in a statement.
Operation IceBridge, a NASA mission that collected surface elevation and radar data from the ice sheet between 2015 and 2017, revealed that Greenland’s double ridge formed after the ice fractured around water that it was refreezing within the ice cap.
The pressure of the water bag caused the different peaks to rise.
This led the researchers to wonder if the same might be possible on Europa, where pockets of water could exist beneath the ice cap, creating potentially habitable environments on the inhospitable layer of the moon.
“In Greenland, this double ridge formed in a location where water from surface lakes and streams often drains near the surface and refreezes,” study lead author Riley Culberg, a student at Greenland, said in a statement. in electrical engineering from Stanford.
“One way similar shallow pockets of water could form on Europa could be through subterranean ocean water being forced into the ice sheet through fractures, and that would suggest there could be a reasonable amount of exchange within the ice sheet”.
A constantly changing lunar surface
Europa appears to be a dynamic place, where columns of water rise through cracks in the ice sheet, which is tens of kilometers thick. And this ice sheet could be a place where the underground ocean and nutrients mix.
“Because it’s closer to the surface, where you get interesting chemicals from space, other moons, and the volcanoes of Io (another moon orbiting Jupiter), there’s a chance life has a chance if there are pockets of water in the shell”. Professor Schroeder said.
“If the mechanism we see in Greenland is how these things happen in Europe, it suggests that water is everywhere.”
This was the first time scientists were able to see something similar happening on Earth and actually look at the subsurface processes that led to the formation of the ridges, Dr. Culberg said.
“The mechanism we present in this paper would have been almost too bold and complicated to propose without seeing it happen in Greenland,” said Professor Schroeder.
The extensive data the team has already collected on the Greenland ice sheet may allow them to use it as an analog for dynamical processes occurring in Europe in the future as well.
The temperature, chemistry and pressure are different in Europe compared to Greenland, so the team wants to investigate how these pockets of water work in Europe.
Hubble photos show the ‘intense and violent’ formation of a giant planet
Europa is the target of two upcoming missions, the European Space Agency’s JUICE (short for Jupiter Icy Moons Explorer) and NASA’s Europa Clipper.
Clipper will carry ice-penetrating radar, similar to how the researchers surveyed Greenland, to collect subsurface images of Europe’s ice sheet.
Europa stands out as one of the best candidates to host extraterrestrial life in our solar system because of liquid water in the subterranean ocean and what scientists understand about its chemistry, Dr. Culberg said.