A hidden ocean at the origin of CO2 on Europa

A hidden ocean at the origin of CO2 on Europa, a moon of Jupiter – Radio-Canada.ca

The carbon dioxide discovered on one of Jupiter’s moons, Europa, comes from an ocean beneath its thick layer of ice. This is according to data from the James Webb Space Telescope, raising hopes that this hidden water could harbor life.

Scientists believe there is a vast ocean of salt water dozens of kilometers beneath Europa’s icy surface, making this moon an ideal candidate for hosting alien life in our solar system.

However, it is difficult to determine whether this hidden ocean contains the chemical elements necessary for life to emerge. Carbon dioxide (CO2), which, along with liquid water, is one of the basic building blocks of this process, has already been detected on the surface of Europa without its origin being clarified.

To find out, two American research teams used data from the James Webb Space Telescope collected with its infrared observing instrument. They were able to map the surface of Europe, according to two studies published Thursday in the journal Science (New Window).

The largest amount of CO2 was found in a 1,800-kilometer-wide area called the Tara Regio. According to one of the studies, this area is covered by chaotic terrain consisting of ridges and cracks.

It’s not clear what creates this rugged terrain, but it could be that relatively warm water rises from the ocean below to melt surface ice, which over time refreezes and forms new elevations.

The first study used information from the James Webb Telescope to determine whether the CO2 could have come from somewhere else, such as a meteorite.

Conclusion: The carbon ultimately comes from the interior, probably from the moon’s inner ocean, explains Samantha Trumbo, a planetary scientist at the American University of Cornell and lead author of the study, to AFP.

A known component

In the Taga Regio region, scientists also discovered the equivalent of table salt, making this area more yellow than the rest of the white plains of Jupiter’s moon. An element that could also have arisen from the ocean.

Now we have CO2, salt: We are starting to know a little more about Europe’s internal chemistry, emphasizes the planetary scientist.

Using the same data from James Webb, the second study also concludes that the carbon came from Europe.

Europa, one of Jupiter’s three icy moons, is the target of two major space missions to determine whether its mysterious ocean supports the emergence of life.

The European Space Agency’s Juice probe was launched last April, and NASA’s Europa Clipper is scheduled to launch in October 2024.

It will take them eight years to reach Jupiter, the giant of the solar system, and its large moons (Io, Europa, Ganymede and Callisto), discovered by Galileo in 1610.

Olivier Witasse, scientific director of the Juice project for ESA, considers the James Webb Telescope analyzes to be extremely interesting. This allows us to learn more about this ocean, which lies deep beneath the ice and is therefore rather inaccessible at the current level of space exploration, he told AFP.

It is one of the most fascinating places in the solar system for the search for life beyond Earth.

When the Juice probe makes two flybys of Europe in 2032, it will collect a wealth of new information, he expects. Juice will also inspect Ganymede, which also has a subglacial ocean and where carbon has been detected.

The Juice and Europa Clipper missions will not be able to find extraterrestrial life directly, but only to identify conditions that favor its appearance. “We leave this challenge to future missions,” adds Olivier Witasse. In such an extreme environment it could only be primitive life forms such as bacteria.