Updated

New analysis suggests that Ariel, one of Uranus' moons, may once have harbored a subsurface ocean more than 100 miles deep beneath its fractured icy shell. Combined with similar evidence from the moon Miranda, the findings suggest the distant Uranian system could host multiple hidden ocean worlds. The discovery strengthens calls among planetary scientists for a dedicated mission to return to the Uranian system, which has not been closely studied since Voyager 2's flyby decades ago.