Carbon dioxide detected on Jupiter’s moon Europa comes from the vast ocean beneath its icy crust, a study suggests, raising hopes that hidden waters could harbor life.
Scientists are confident that there is a huge ocean of salt water kilometers below Europa’s ice-covered surface, making the moon a prime candidate to host extraterrestrial life in our solar system.
But determining whether this hidden ocean contains the right chemical elements to support life is difficult.
Carbon dioxide, one of the building blocks of life, was discovered on the surface of Europa, but what emerged from the ocean below remained a puzzling question for scientists.
Aiming to find an answer, two US-led teams of scientists used data from the James Webb Telescope’s near-infrared spectrograph to map carbon dioxide on Europa’s surface, publishing their findings in separate studies in the journal Science.
The greatest amount of carbon dioxide was in a 1,800-kilometre-wide (1,120-mile) area called Tara Reggio, where there is a lot of “chaos terrain” with ridges and jagged crevasses.
The exact cause of the chaotic terrain is not well understood, but one theory is that warm water from the ocean rises to melt surface ice, which then freezes over time into new uneven rock.
The first study used James Webb’s data to see if the carbon dioxide came from somewhere other than the ocean below, like a meteorite for example.
Samantha Trumbo, a planetary scientist at Cornell University and lead author of the study, told AFP that they concluded that the carbon was “ultimately derived from the interior, most likely from the inner ocean.”
But scientists couldn’t rule out that the carbon came from the planet’s interior in the form of rock-like carbonate minerals, which could then break down by radiation to become carbon dioxide.
Table salt has also been discovered in Tara Reggio, making the area noticeably yellower than the rest of Europe’s scarred white plains, and scientists believe it may also have come from the ocean.
“We now have salt and carbon dioxide,” Trumbo explained. “We’re starting to learn more about what that internal chemistry might look like.”
Looking at the same James Webb data, the second study noted that “the carbon comes from within Jupiter’s Europa.”
Researchers led by NASA were also hoping to find plumes of water or volatile gases emanating from the moon’s surface, but they failed to detect any.
Two major space missions are planned to take a closer look at Europa and its mysterious surroundings.