Such active geology suggests that Europa’s icy surface is connected to its buried ocean — creating a possible pathway for salts, minerals and maybe even microbes to get from the ocean to the surface and back again.
Places have already been spotted on Europa where fresh ice crust is being born, but the latest research is the first to pinpoint where it might be going to die.
But without high-resolution images from more areas, researchers cannot tell whether subduction might also be happening in other locations. If it turns out to be common, it might mean that the moon could be cycling life-friendly compounds between the surface and the deep, and that substantially increases the chance that its ocean is habitable, says Michael Bland, a planetary scientist at the US Geological Survey in Flagstaff, Arizona.
The discovery adds to excitement set off in December, when scientists reported plumes of water vapour spurting out at Europa’s south pole (L. Roth et al. Science 343, 171–174; 2014). The plumes have not been seen since, and they may or may not be related to Europa’s newly appreciated system of plate tectonics. NASA now needs to figure out what kind of mission might best to explore these discoveries.