Jupiter’s moon may have a habitable ice sheet, study says

On Jupiter’s moon Europa there is an ocean of salt water deep in a thick layer of ice. Now, a surprising connection between Earth’s ice sheet and the Greenland ice sheet has provided new insight: the ocean on the moon Europa may be habitable, according to a new study.

Scientists have been puzzled for more than 20 years by dramatic cuts in Europa’s icy surface. These double ridges have ridges that can reach nearly 305 meters in height, with wide valleys between them.

These features were first imaged by NASA’s Galileo spacecraft in the 1990s, but researchers haven’t 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 M-shaped double ridge feature that is like a mini-version of Europa.

A study detailing the findings was published Tuesday in the journal Nature Communications.

Impact of water on topography of the ice sheet

Aerial instruments help researchers study Earth’s polar regions to observe changes in ice sheets that could affect global sea levels.

These eyes in the sky also look for surface meltwater ponds, conduits carrying 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. We could see the ridges go from ‘unformed’ to ‘formed,'” Dustin Schroeder, associate professor of geophysics at Stanford University’s School of Earth, Energy and Environmental Sciences, said 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 the Greenland double ridge formed after ice fractured around water that was refreezing within the ice sheet. ice layer. The pressure of the water bag caused the distinct peaks to rise.

This has led researchers to question whether the same thing would be possible on Europa, where pockets of water could exist beneath the ice sheet and create potentially habitable environments in the moon’s inhospitable layer.

“In Greenland, this double ridge formed at a place where water from surface lakes and streams often drains to the nearby surface and freezes again,” said lead study author Riley Culberg, a doctoral student in electrical engineering at Stanford. , in a statement.

“One way that similar pockets of shallow water could form on Europa could be through subterranean ocean water being forced into the ice shell through fractures – and this would suggest that there could be a fair amount of exchange going on within the ice shell. ice shell.”

An ever-changing lunar surface

Europa appears to be a dynamic place, where clouds of water rise through cracks in the ice sheet, which is tens of kilometers thick. And that ice shell could be a place where the subterranean ocean and nutrients mingle.

“Because it’s closer to the surface, where you get interesting chemicals from space, other moons, and volcanoes on Io (another moon orbiting Jupiter), there’s a possibility that life has a chance if there are pockets of water in the shell. “, he said. said Schroeder. “If the mechanism we see in Greenland is how these things happen in Europe, then that suggests there’s water everywhere.”

This was the first time that scientists were able to observe something similar happening on Earth and actually observe the underground processes that led to the formation of the ridges, Culberg said.

“The mechanism we present in this paper would have been almost too audacious and complicated to propose without seeing it happen in Greenland,” Schroeder said. The extensive data the team has already collected about the Greenland ice sheet may allow them to use it as an analogue for dynamic processes taking place 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.

Europa is targeted by two upcoming missions, the European Space Agency’s Juice (short for Jupiter Icy Moons Explorer) and NASA’s Europa Clipper. Clipper will carry an ice-penetrating radar, similar to the way the researchers studied Greenland, to collect subsurface images of Europa’s ice shell.

The moon Europa stands out as one of the best candidates for hosting extraterrestrial life in our Solar System because of the liquid water in the subterranean ocean and what scientists understand about its chemistry, Culberg said.