The carbon dioxide detected in one of the moons of JupiterEuropa, originates from an ocean hidden under a thick layer of ice, according to data collected by the James Webb Space Telescope and raise hopes that this water could support life.

Scientists are convinced that a huge ocean of salt water lies at a depth of several tens of kilometers below the icy surface of Europa.

This fact makes it an ideal candidate to host alien life, in some form.

It is however difficult to determine whether this hidden ocean contains those chemical elements necessary for life to appear. Carbon dioxide (CO2), which, along with water, is one of the fundamental building blocks of this process, had already been detected on Europa’s surface, but its origin had not been determined.

To solve the mystery, two groups of American researchers used data collected by the James Webb Space Telescope. They thus managed to map the surface of Europa, according to two studies published today in the scientific journal Science.

The largest amount of CO2 was found in a zone 1,800 km wide, called Taga Reggio. This zone is covered by “chaotic terrain”, with ridges and faults.

It is not clear how this “lacy” surface was created.

It may be that the relatively warm water of the subsurface ocean rises, melting the ice, which over time refreezes to create elevations.

Like table salt

The first study used information from the James Webb Telescope to determine whether the CO2 could have come from another source, for example, a meteorite. The bottom line: carbon dioxide “comes from the interior, probably from the moon’s hidden ocean,” explained Samantha Trumbo, a planetary scientist at Cornell University in the US who led the study.

In the Taga Reggio zone, scientists also identified an element similar to table salt. Because of this, the area is more yellow than the other, white areas of Europe. This element may also have emerged from the ocean.

“Now, we have CO2 and salt: we’re starting to learn more about the internal chemistry” of Europa, Trumbo said.

Based on the same James Webb data, the second study also concludes that the carbon dioxide originates from within Europe.

Europa, one of Jupiter’s three icy moons, is the target of two major space missions that hope to solve the mystery of its ocean.

ESA’s Juice spacecraft launched last April, while Nasa’s Europa Clipper will launch in October 2024.

It will take eight years to reach Jupiter and its large moons, Io, Europa, Ganymede and Callisto, discovered by Galileo in 1610.