Pluto's moons are named for characters associated with the underworld of Greek and Roman mythology.
Charon is Pluto's largest moon. It was discovered in June 1978.
Pluto's moons Nix and Hydra were discovered in June 2005.
Kerberos was discovered on June 28, 2011, by astronomers using Hubble Space Telescope.
The Hubble Space Telescope also found Styx, Pluto's fifth and smallest moon, on June 26, 2012.
Pluto's moons to scale. The largest, Charon, is displayed along the bottom.
Pluto's moon system – Charon, Nix, Hydra, Styx, and Kerberos – is believed to have formed after a collision between Pluto, and another Kuiper Belt Object early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto.
All of Pluto's moons are named for mythological figures associated with the underworld, a naming convention that started when 11-year-old Venetia Burney named Pluto in 1930.