NASA's James Webb Telescope may have found the source of Europa's carbon

Scientists believe carbon dioxide on the moon came from its subsurface ocean.

Mariella Moon
·Contributing Reporter
Updated Fri, September 22, 2023 

NASA/JPL/University of Arizona


Before the Galileo spacecraft was destroyed two decades ago, it detected several chemicals on the surface of Jupiter's moon Europa, including carbon dioxide. Now, a couple of studies using observations by the James Webb Space Telescope (JWST) suggest that the carbon dioxide on Europa's surface came from the ocean hidden underneath its icy shell. Further, the researchers have come to the conclusion that it's pretty recent in origin — geologically speaking, at least.

The observations made using the telescope's Near-Infrared Spectrograph (NIRSpec) instrument showed scientists that the carbon dioxide on Europa is most abundant in an area called Tara Regio, or "chaos terrain." In the images above, you'll see Tara Regio as the yellowish area to the left of the moon's center.

Emily Martin, a planetary geologist at the National Air and Space Museum, told Scientific American that scientists believe Tara Regio's ice surface broke up when the weather got warm enough at one point. That caused the water from the subsurface ocean to come up, until it got cold again to create a slushy icy water sort of area. It's worth noting that previous Hubble observations of the region show that it also contains table salt, which indicates that saltwater, indeed, could've risen up to the surface of the moon.

If Europa's carbon dioxide truly did come from its ocean instead of from meteors or other sources, then it would establish a big similarity between our planet and the moon. Europa is one of the objects in our solar system that's under observation for potentially having the conditions to support life. In April this year, the European Space Agency launched the Jupiter Icy Moons Explorer or JUICE to make detailed observations of the planet's ocean-bearing moons Ganymede, Callisto and Europa. Meanwhile, NASA's Europa Clipper spacecraft, which will focus on the potential for life in the moon's ocean, is scheduled to take off sometime next year.

Astronomers say carbon dioxide on Jupiter's moon Europa likely originated in ocean

Fri, September 22, 2023 

NIRCam (the Near Infrared Camera) on NASA’s James Webb Space Telescope captured this picture of the surface of Jupiter’s moon Europa. Webb identified carbon dioxide on the icy surface of Europa that likely originated in the moon’s subsurface ocean. Photo courtesy of NASA

Sept. 22 (UPI) -- Data from NASA's James Webb Space Telescope shows carbon dioxide on a region of Jupiter's moon Europa, suggesting it potentially could harbor conditions suitable for life.

Astronomers found carbon dioxide on the icy surface of a region called Tara Regio, and analysis from two studies suggests it likely originated in the moon's subsurface ocean.

"Understanding the chemistry of Europa's ocean will help us determine whether it's hostile to life as we know it, or if it might be a good place for life," Geronimo Villanueva, of NASA's Goddard Space Flight Center, said in a news release.

Villanueva is the lead author of one of the studies. Using Webb's Near-Infrared Spectrograph instrument, researchers determined the chemical composition of ice by measuring the amount of light at different wavelengths.

"We now think we have observational evidence that the carbon we see on Europa's surface came from the ocean. That's not a trivial thing. Carbon is a biologically essential element," Samantha Trumbo, of Cornell University in Ithaca and lead author of the other paper, said.

Heavy concentrations of carbon dioxide in the salty Tara Regio region, where the surface ice has been disrupted, suggest the carbon originated deep in the ocean. This suggests a similarity with Earth's deep-sea hydrothermal vent systems, where life on Earth may have originated, Scientific American reported.

Villanueva's looked for a plume of water vapor but found no evidence in the new Webb data. Plumes were tentatively detected in previous research, suggesting they could be variable.

"This work gives a first hint of all the amazing solar system science we'll be able to do with Webb," Heidi Hammel of the Association of Universities for Research in Astronomy, said in the NASA news release.

In October 2024, NASA is set to launch its Europa Clipper spacecraft, which will further study the possibility of life-sustaining conditions on Europa.