The International Astronomical Union (IAU) has announced that Pluto's fourth and fifth moons have been named Cerberus (Kerberos) and Styx (Styx) . They are the winning names of a contest organized among Internet users that has had more than 500,000 votes. The names have been the second and third most voted by Internet users, since the body has rejected the most popular option, which was Vulcano , due, among other things, to the fact that it had already been used in astronomy to designate a hypothetical planet located between Mercury and the Sun, which ultimately turned out to be non-existent.
The new moons of Pluto were discovered in 2011 and 2012 with the help of the Hubble Space Telescope's WFC3 (Wide Field Camera) camera . Cerberus has an estimated diameter of 13 to 34 kilometers, while Styx is irregular and its longest side is estimated to reach between 10 and 25 kilometers.
In Greek mythology Cerberus or Can Cerberus was the three-headed dog that guarded the door of Hades, and Styx was the lagoon or river that separated the world of the living from that of the dead. The other moons of Pluto were also baptized with mythological names: Charon, Nix, and Hydra.
