Pluto's Frozen Ocean May Have Been Liquid

A frozen subsurface ocean may have caused Pluto's largest moon, Charon, to begin bursting at the seams, much like Marvel's green superhero the Hulk. A newly released image of Charon from NASA's New Horizons spacecraft suggests that some of the fractures on that moon's surface may be the result of a once-liquid ocean beneath the surface freezing over time.