Ariel, one of Uranus' moons, may once have contained a subsurface ocean more than 100 miles deep beneath its fractured icy shell, according to a new analysis. The fractures in Ariel's surface are consistent with a buried ocean that has since changed or disappeared, leaving behind clues in the moon's geology.
The finding echoes previous evidence from Miranda, another Uranian moon. Taken together, the two moons suggest that the distant Uranian system could harbor multiple hidden ocean worlds, raising the possibility that such environments were once more common in the outer solar system than previously thought.
Because Uranus has not been the focus of a dedicated orbiter mission, scientists say this evidence strengthens the need to return. The study highlights how much remains unknown about the ice giants and their moons, and why a closer look could reshape our understanding of where subsurface oceans might exist.