Europa is Jupiter’s fourth largest moon and is believed to have a sizable liquid water ocean under its thick layer of ice.
Now, a team of scientists from Stanford University in the US has explored the similarities between the double ridges on the surface of the moon Europa and smaller versions of the features found under the ice of Greenland, here at the earth. The striking resemblance between the two features suggests that the icy moon may be capable of supporting life.
the same geometry
To explore the formation of the Greenland ridge, the researchers used surface elevation data and radar soundings that indicate it formed through a succession of refreezing, pressurization, and fracturing of a shallow water sill within the layer. of ice. If this process is equally responsible for the formation of double ridges on Europa, it may indicate that there is shallow liquid water in the ice shell of Jupiter’s fourth largest moon.
These ridges can extend for hundreds of kilometers and include some of the oldest features visible on the surface, with frequent cross-sections involving numerous cycles of formation throughout Europa’s history.
“If you were to slice one up and look at the cross section, it would look a bit like the capital letter M ,” said Stanford University geophysicist Riley Culberg, lead author of the study published in the journal Nature Communications.
We have known about these features since NASA’s Galileo spacecraft photographed the moon’s surface in the 1990s.
Alien life in our own cosmic neighborhood?
It is an exciting possibility . Its deep saltwater ocean is intriguing, though its thick icy outer layer, which is dizzyingly 20 to 30 km thick, could become a barrier to future sampling missions . But this study provides evidence that the icy layer might be less obstructive than we thought.
In the search for extraterrestrial life, Europa has long drawn attention as one of the places in our solar system that may be habitable , perhaps by microbes, due to the global ocean of salty water detected deep within its ice cap. And finding pockets of water near the surface would provide a second potential habitat for organisms.
“One way that similar shallow pockets of water could form on Europa could be through subterranean ocean water being forced up into the ice sheet through fractures, and that would suggest there could be a reasonable amount of exchange within the ice sheet,” says Dustin Schroeder, co-author of the paper.
Europa appears to undergo a variety of geological and hydrological processes, an idea supported by this study and others, including evidence of plumes of water rising to the surface.
“Because it’s closer to the surface, where you get interesting chemicals from space, other moons and Io’s volcanoes, there’s a chance life has a chance if there are pockets of water in the ice sheet,” he says. Dustin Schroeder, co-author of the work.
upcoming missions
NASA’s Europa Clipper robotic spacecraft is scheduled for a 2024 launch to further investigate whether this moon possesses the right conditions for life. In 2030 Clipper will be orbiting the moon , providing new insights based on this theory and many others. Meanwhile, NASA’s James Webb Space Telescope is gearing up to search for alien life in distant solar systems this year.
Europa is the fourth largest of Jupiter’s 79 known moons, slightly smaller than Earth’s moon but larger than the dwarf planet Pluto , and its ocean could hold twice as much water as Earth’s.
Referencia: R. Culberg et al. 2022. Double ridge formation over shallow water sills on Jupiter’s moon Europa. Nat Commun 13, 2007; doi: 10.1038/s41467-022-29458-3
