Astronomers using data from the NASA/ESA/CSA James Webb Space Telescope have made an important discovery about Jupiter’s moon Europa. Previous research has shown that Europa has a salty ocean of liquid water beneath its icy crust, making it a potential candidate for hosting life. However, scientists had not confirmed whether the ocean contained the necessary chemicals for life, particularly carbon.
The new findings reveal that carbon dioxide has been identified in a specific region on Europa’s icy surface. Analysis of the data suggests that this carbon likely originated from the subsurface ocean and was not delivered by meteorites or other external sources. Furthermore, the carbon dioxide was deposited on the surface relatively recently. This discovery has significant implications for the potential habitability of Europa’s ocean.
The presence of carbon is crucial for life as we know it on Earth. Geronimo Villanueva of NASA’s Goddard Space Flight Center and Samantha Trumbo of Cornell University explain that understanding the chemistry of Europa’s ocean will help determine whether it is suitable for life or not.
The carbon dioxide was found to be most abundant in a region called Tara Regio, which is a geologically young area known as “chaos terrain.” This region has experienced disruptions in its surface ice, suggesting an exchange of material between the subsurface ocean and the icy surface. Previous observations from the Hubble Space Telescope have also shown evidence of ocean-derived salt in Tara Regio, further supporting the idea that the carbon likely originated from the internal ocean.
The discovery was made using data from the Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope. The instrument provided high-resolution spectra, allowing astronomers to determine the location of specific chemicals on Europa’s surface.
The scientists note that carbon dioxide is not stable on Europa’s surface, indicating that it was supplied relatively recently. Its concentration in a region of young terrain supports this conclusion.
In addition to studying carbon dioxide, the researchers also looked for evidence of water vapor plumes erupting from Europa’s surface. Previous observations with the Hubble Space Telescope had reported tentative detections of plumes, but definitive proof has been elusive. The new Webb data did not show any evidence of plume activity, but the researchers emphasize that this does not rule out the presence of plumes.
These findings have important implications for future missions to Europa, such as NASA’s Europa Clipper and ESA’s Jupiter Icy Moons Explorer (Juice). Juice, which was launched in April 2023, will study Jupiter and its three large ocean-bearing moons, including Europa. The mission aims to characterize these moons as potential habitats and explore Jupiter’s complex environment.
The researchers are excited about the potential of the James Webb Space Telescope for further discoveries about Jupiter’s moons. They believe that future observations with instruments like Juice’s MAJIS instrument will provide even more detailed information about the surface properties and habitability conditions of Europa.
The two papers describing these findings will be published in Science on September 21, 2023.