Jupiter’s icy moon Europa may have an active system of plate tectonics, according to a study published online in Nature Geoscience. Previously, the only body in our solar system known to have been shaped by a network of moving tectonic plates was Earth.

Simon Kattenhorn and Louise Prockter used images from NASA’s Galileo spacecraft, which orbited Jupiter and its moons until 2003, to reconstruct the geological history of a portion of Europa’s icy surface that is criss-crossed by ridges and fractures. They found evidence that a piece of the surface had been removed along a boundary between two plates of ice. The authors suggest that at this boundary one plate of ice sank beneath the other into warmer ice layers beneath. This process is similar to the sinking of parts of the Earth’s oceanic crust into the underlying mantle at zones where tectonic plates converge and suggests that a plate tectonic system is operating on Europa.

In an accompanying News and Views article, Michelle Selvans writes that “icy Europa may be more tectonically similar to rocky Earth than any other planetary body we know of.”