A new study from NASA has produced evidence to suggest that an ocean on Jupiter’s moon Europa is capable of sustaining life. The scientists also determined that the ocean was likely formed when tidal forces or radioactive decay broke down water-containing minerals.
Though slightly smaller than Earth’s moon, Europa is one of the largest moons in the solar system. For decades, scientists have theorized that the surface of the moon floats on a subsurface ocean, but the origin and composition of the ocean has remained a mystery.
Using data from the Galileo mission, researchers at NASA’s Jet Propulsion Laboratory modeled geochemical reservoirs within the interior of Europa.
“We were able to model the composition and physical properties of the core, silicate layer, and ocean. We find that different minerals lose water and volatiles at different depths and temperatures,” said lead researcher Mohit Melwani Daswani.
“We added up these volatiles that are estimated to have been lost from the interior, and found that they are consistent with the current ocean’s predicted mass, meaning that they are probably present in the ocean.”
The study revealed that ocean worlds such as Europa can be formed by the heating and pressure caused by early radioactive decay or later tidal movement. These processes could break down minerals that contain water, which would then be released.
The analysis also indicates that the ocean would have initially been mildly acidic, with high concentrations of carbon dioxide, calcium, and sulfate.
“Indeed it was thought that this ocean could still be rather sulfuric, but our simulations, coupled with data from the Hubble Space Telescope, showing chloride on Europa’s surface, suggests that the water most likely became chloride rich. In other words, its composition became more like oceans on Earth. We believe that this ocean could be quite habitable for life,” explained Daswani.
“Europa is one of our best chances of finding life in our solar system. NASA’s Europa Clipper mission will launch in the next few years, and so our work aims to prepare for the mission, which will investigate Europa’s habitability.”
“Our models lead us to think that the oceans in other moons, such as Europa’s neighbor Ganymede, and Saturn’s moon Titan, may also have formed by similar processes. We still need to understand several points though, such as how fluids migrate through Europa’s rocky interior.”
Using high-resolution imaging, NASA is searching for possible sites on Europa to test the study findings.
The research was presented at the virtual Goldschmidt Conference.