Recently, we’ve learned that Pluto is a double (dwarf) planet in combination with its mutually tidally locked partner, Charon (pronounced Karen). No matter which “dwarf” you are on, the same side of the other will always face you. Charon cannot see Pluto’s heart, which is on Pluto’s “dark side,” relative to its view.
Now called Tombaugh Regio, Pluto’s (unrequited) heart is a lake of frozen nitrogen, a dense feature that skews the orbits of these two bodies, so that they both orbit a center of mass for this system that’s actually above the surface of Pluto.
Charon will never see Tombaugh Regio, though it’s gravity is strongly felt, inspiring this haiku:
Pluto’s heavy heart,
is lost on Charon.