Newswise — Jupiter's moon Europa is one of the few worlds in our solar system capable of harboring conditions suitable for life. Previous studies have shown that beneath its water ice crust is a liquid water salty ocean with a rocky sea floor. However, planetary scientists have not confirmed whether this ocean contained the chemicals necessary for life, especially carbon.
Using data from NASA's James Webb Space Telescope, astronomers have detected carbon dioxide in a specific region of Europa's icy surface. The analysis shows that this carbon likely originated in the subsurface ocean and was not supplied by meteorites or other external sources. Moreover, it was deposited at a geologically recent time. This finding has important implications for the potential habitability of Europa's oceans.
“Life on Earth loves chemical diversity—the more diversity, the better. We are carbon based life. “Understanding the chemistry of Europa's ocean will help us determine whether it is hostile to life as we know it, or could be a good place for life,” said Jeronimo Villanueva of NASA's Goddard Space Flight Center in Greenbelt, Maryland, one of the lead authors. Two independent papers describing the findings.
“We now think we have observational evidence that the carbon we see on Europa's surface came from the ocean. This is not a trivial thing. Carbon is a biologically essential element,” added Samantha Trumbo of Cornell University in Ithaca, New York, lead author of a second paper analyzing the data.
NASA plans to launch it Europa Clipper spacecraftIt will make dozens of close flybys of Europa in October 2024 to further investigate whether it might have conditions suitable for life.
Surface Ocean Connection
Webb finds that carbon dioxide on Europa's surface is most abundant in a region called the Tara Regio—a geologically young area of generally restored terrain known as the “Chaos Terrain.” The surface ice was broken up and there was probably an exchange of material between the subsurface ocean and the icy surface.
“Previous Hubble Space Telescope observations show evidence of ocean-derived salt at Tara Reggio,” Trumbo explained. “Now we see that carbon dioxide is also highly concentrated there. We think this implies that carbon is likely to have its ultimate origin in the interior ocean.
“Scientists are debating to what extent Europa's ocean is connected to its surface. “I think that question was a big driver of the search for Europe,” Villanueva said. “This suggests that we can learn some basic things about ocean composition even before we drill through the ice to get the full picture.”
Both teams identified carbon dioxide as derived using the data integral field unit Webb's Near Infrared Spectrograph (NIRSpec). This instrument mode provides spectra with a resolution of 200 x 200 miles (320 x 320 kilometers) over the surface of Europa, which is 1,944 miles in diameter, allowing astronomers to determine where specific chemicals are located.
Carbon dioxide is not stable on Europa's surface. Therefore, scientists say it is likely to have been supplied by geologically recent time—a conclusion supported by its concentration in a region of young terrain.
“These observations took only a few minutes of the observatory's time,” said Heidi Hammel of the Association of Astronomical Research Universities, a Webb Interdisciplinary Scientist who led Webb's Cycle 1 Guaranteed Time observations of the Solar System. “Even in this short time, we were able to do some really great science. This work provides the first hint of all the amazing solar system science we'll be able to do with the Web.”
Looking for plums
Villanueva's team also looked for evidence of water vapor erupting from Europa's surface. Using NASA's Hubble Space Telescope, researchers reported the probable detection of the plume. 2013 year, 2016 yearand 2017 year. However, definitive proof was difficult to find.
Webb's new data show no evidence of plume activity, which allowed Villanueva's team to put a tight upper limit on the rate of potentially ejected material. However, the team emphasized that their detection does not rule out a plume.
“There's always the possibility that these feathers are variable and you can only see them at certain times.” “We can only say with 100% certainty that we did not detect a plume on Europa when we made these observations with Webb,” Hammel said.
These findings could help inform NASA's Europa Clipper mission, as well as ESA's (European Space Agency) future explorer of Jupiter's icy moons.juice).
Two papers will be published on September 21.
For more information or to download full resolution images, go to https://webbtelescope.org/contents/news-releases/2023/news-2023-113.
The James Webb Space Telescope is the world's premier space science observatory. Webb unravels mysteries in our solar system, searches for distant worlds around other stars, and explores the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners ESA (European Space Agency) and the Canadian Space Agency.