ancient ocean

Pluto’s ‘Hulk-like’ Moon Charon: A Possible Ancient Ocean?

Pluto’s ‘Hulk-like’ Moon Charon: A Possible Ancient Ocean?

Pluto’s largest moon may have gotten too big for its own skin. Images from NASA’s New Horizons mission suggest that Pluto’s moon Charon once had a subsurface ocean that has long since frozen and expanded, pushing outward and causing the moon’s surface to stretch and fracture on a massive scale.