Europa's seafloor may lack the geological activity needed to support life

A Nature Communications study led by Paul Byrne models Europa's interior and reports little evidence for seafloor tectonics or hydrothermal activity, which the authors say reduces the likelihood of life on the ocean floor.

New research led by Paul Byrne models Europa's internal structure and reports that the moon's seafloor is likely geologically quiet. Europa is known for a thick ice shell over a global ocean, which has made it a focal point in discussions about possible extraterrestrial life. The study combined measurements and comparisons with other planetary bodies to assess whether the seafloor could host energy sources like tectonics or hydrothermal vents. The authors conclude that, under present conditions, there appears to be little seafloor activity. Key findings: - The study used models of Europa's size, internal structure, and the gravitational influence of Jupiter to assess internal heating. - Researchers report little evidence for active seafloor tectonics, hydrothermal vents, or other strong energy sources that typically support ocean-floor ecosystems. - Europa's ice shell is estimated at about 15–25 km thick, and the underlying ocean may reach depths up to roughly 100 km. - The team calculated that Europa's rocky core likely cooled long ago and that internal heat would have dissipated billions of years in the past. - The study notes that tidal heating on Europa is weaker than on Io, reducing the potential for sustained seafloor geological activity. - The paper was published in Nature Communications; co-authors include Philip Skemer, Jeffrey Catalano, Douglas Wiens, and Henry Dawson. Summary: The authors report that their models reduce the likelihood of current energetic seafloor environments on Europa, which they say makes present-day life on the ocean floor less likely. Future measurements from NASA's Europa Clipper mission, scheduled for flybys beginning in spring 2031, are expected to improve estimates of the ice shell and ocean and provide more certainty.