Europa, the icy moon of Jupiter, is an oceanic world covered in a thick crust of ice. A place where snow floats up.
Underwater ice forms in the World Ocean and rises through the water to connect to submerged valleys and inverted ice peaks, according to new research. This same phenomenon occurs under the Earth’s ice shelves, and this is probably how the moon Europa creates its ice sheet.
The result was published on Monday in the magazine astrobiology, suggested that the ice sheet on Europa may not be as salty as scientists first thought. Understanding the salt content of the ice crust is critical, as engineers are already working on assembling NASA’s Europa Clipper spacecraft, which is scheduled to launch on Europa in October 2024.
This illustration shows the Europa Clipper spacecraft flying over an icy moon, with Jupiter in the background.
The Europa Clipper will use ice-penetrating radar to see beneath the layer and determine if the moon’s ocean is habitable. The presence of salt within the ice sheet may prevent radar from going deeper, so predictions about the formation of the ice sheet are critical.
Clues about the ice sheet could also help scientists learn more about Europe’s ocean, its salinity, and its habitability.
The ice sheet on Europa is between 15 and 25 kilometers thick and is believed to lie on top of a sea with a depth of 60 to 150 kilometers.
The lead author of the study said: “As we explore Europa, we are interested in salinity and ocean composition, as this is one of the aspects that will determine its potential habitability or even the type of life it can live.” Statement, Natalie Wolfenberger, PhD student and researcher in the University of Texas Geophysics Institute, Department of Earth Sciences.
Natalie Wolfenberger is also part of the Europa Clipper science team. In Austin, researchers at the University of Texas are developing an ice-penetrating radar for the spacecraft.
Previous studies suggested The ocean of Europa closest to its ice sheet has a temperature, pressure, and salinity similar to the water beneath the ice shelves in Antarctica.
Researchers have studied two methods of freezing water under ice shelves on Earth: freezing ice and brittle ice.
What is the difference? Frozen ice grows under the ice shelf, while fragile ice cascades through sea ice before settling beneath the ice shelf.
Both produce ice that is less salty than seawater—and according to the researchers’ predictions, the seawater was less salty when they applied this data to the age and size of the ice sheet on Europa.
Fragile ice is thought to be the most common type on Europa’s moon, making the ice sheet much purer than previously thought. Fragile ice keeps a small portion of the salt in seawater. The purity of the ice sheet can affect its strength, the tectonics of the ice and the way heat flows through the ice sheet.
“We can use Earth to assess the habitability of Europa, analyze the exchange of impurities between the ice and the sea, and see where the water is in the ice,” said study co-author Donald Blankenship, a senior scientist at the University of Texas Geophysics Institute. He is the principal investigator for the Europa Clipper ice-penetrating radar.
The discovery could indicate that the Earth can be used as a model for a better understanding of Europa’s habitation.
Previous missions have observed plumes of water vapor erupting across the ice sheet, as shown in this illustration.
“This work opens up a whole new set of possibilities for thinking about ocean worlds and how they work,” Steve Vance, a researcher at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement. “This will determine how we prepare to analyze the ice at Europa Clipper.” Vance was not involved in the study.
Meanwhile, work is underway on the Europa Clipper spacecraft, in the assembly unit at NASA’s Jet Propulsion Laboratory.
The core, which is 3 meters high and 1.5 meters wide, played a central role in the sterile chamber, where NASA teams have installed space probes such as Galileo or Cassini and Rovers From Mars.
The mission team is currently assembling the Europa Clipper on High Bay 1, a sterile room at NASA’s Jet Propulsion Laboratory, where other historic missions are set up before launch.
Aeronautical equipment and instruments will be installed on the spacecraft by the end of the year. Then, engineers will run a series of tests during the preparatory period for takeoff.
The Europa Clipper will reach the Jovian moon in April 2030. After about 50 planned flights over Europa, the spacecraft will travel from an altitude of 2,735 kilometers to just 25 kilometers above the lunar surface.
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