Ariel may once have held a subsurface ocean more than 100 miles deep

Research published in Icarus suggests Uranus's moon Ariel once held a subsurface ocean more than 100 miles (170 km) deep beneath its icy shell. Combined with similar evidence from Miranda, the findings suggest the Uranian system may harbor multiple hidden ocean worlds. Ariel, 720 miles across and the system's fourth-largest moon, shows fractures and young terrain that may reflect cryovolcanism.