Charon’s surface cracked when ancient subsurface sea froze

Chasms on Pluto’s largest moon rival the Grand Canyon — and then some

Charon's surface

TORN APART  Parts of Charon’s surface, seen in this image from the New Horizons spacecraft, appear to have been pulled apart, possibly by the freezing and expanding of a subsurface ocean. 

NASA, JHUAPL, SWRI

Pluto’s largest moon Charon is busting at the seams, and an ancient subsurface ocean might be to blame.