Venetia Burney, an eleven-year-old schoolgirl in Oxford, England, who was interested in classical mythology, suggested the name in a conversation with her grandfather Falconer Madan, a former librarian at the University of Oxford's Bodleian Library, who passed the name to astronomy professor Herbert Hall Turner, who cabled it to colleagues in the United States.

Charon hovers over the same spot on Pluto -- and the same side of Charon always faces Pluto. Nix, Hydra, Styx, and Kerberos appear to rotate chaotically. This is because they are in a dynamically changing gravitational field caused by Pluto and Charon orbiting each other. It could actually be possible to spend a day on Nix in which the sun rises in the east and sets in the north!

Tombaugh Regio, nicknamed The Heart after its shape, is the largest bright surface feature on Pluto. The feature had been identified as a bright spot for six decades prior to the New Horizons flyby, although it was impossible to image it with enough resolution to determine its shape. During that time, the spot has been observed to be dimming.

In September 2016, astronomers announced that the reddish-brown cap of the north pole of Charon is composed of tholins, organic macromolecules that may be ingredients for the emergence of life, and produced from methane, nitrogen and other gases released from the atmosphere of Pluto and transferred about 19,000 km (12,000 mi) to the orbiting moon.