Scientists do not rule out that pockets of water are stored under the icy surface of Europa, one of Jupiter’s moons, and they base their hypotheses on what they concluded from observations of the surface of Greenland.
Research on the possibility of the existence of life forms in the solar system outside the planet is focused on Europa, given that an ocean of liquid water may be present in it, but it is believed that it is located under a thick layer of ice, at a depth of up to 20 to 30 kilometers below the surface, According to data collected by space probes.
But a study published Tuesday in the journal Nature Communications indicated that some of this water may be much closer to the surface than previously thought, and described Europa as “newly existing and geologically active.”
And overpowering Jupiter are double hills that are like grooves that can extend hundreds of kilometers, and their edges may reach hundreds of meters in height.
Scientists presented several hypotheses to explain its formation, most notably the interaction between the inner ocean and the layer of ice covering it. But the difficulty of water passing through such a thick surface has led to the belief that the ridges are formed by the presence of pockets of water just below the surface.
This type of terrain is exactly what a team of geophysicists from Stanford University in the United States has also observed in Greenland, an island covered mainly with ice.
The lead author of the study, a doctoral student in electrical engineering at Stanford University Riley Kallberg, explained that he and his colleagues discovered in Greenland “a chain of double ice ridges with a shape similar to that found in Europa.” It is about 800 meters long and has an average height of 2.1 meters, and is located about 60 kilometers from the coast in northwest Greenland.
His colleague, professor of geophysics at Stanford University, Dustin Schroeder, said the team was doing research “on a completely different topic of climate change and its impact on Greenland’s surface” when they noticed “these little double mounds”.
Reilly Kallberg explained that satellite imagery and data from airborne radar made it possible “for the first time to see something similar[to Europa]on Earth, and to see what’s going on beneath the surface that leads to the formation of hills.”
The team prepared a model for the various stages of the phenomenon, i.e. the freezing of a shallow pocket of water and subjecting it to pressure and fracture, which leads to the formation of the double edge.
“The water we detected in Greenland is in the first 30 meters under the ice sheet,” Kallberg said. In Europa, where the edges are much higher and longer, it is likely that “water pockets are formed at a depth of between one and five kilometers,” he explained.
Thus, if the mechanism of formation is indeed the one predicted by the study, these pockets may be widespread. And if the water it is made of comes from the inner ocean, it could contain traces of extraterrestrial life.
Two future space missions will allow more discovery, starting in 2030. The Europa Clipper spacecraft of the US Space Agency (NASA) will be equipped with a radar similar to that used in the study of Greenland. The European Space Agency’s JOS spacecraft will also study Europa and two other icy moons of Jupiter, Io and Ganymede.
(AFP)