The new moon Pluto is officially named

The International Astronomical Society (IAU) has decided to officially name the two new moons of Pluto, Kerberos and Styx.

The fourth and fifth moons of Pluto are officially new names - (Photo: BBC News)

Previously these two moons were referred to as P4 and P5 for short.

The three moons have the name of Pluto: Charon (named after the boatman crossing the Styx River), Nix (the Goddess of the Night) and Hydra (the head of the multiple-headed soap), based on mythical characters Greece.

The official name of the fourth and fifth moons also comes from myths, one refers to a three-headed dog, the other is a river that separates life and death.

Kerberos and Styx are very small, with a diameter of 20-30km. They were discovered when NASA began its mission of 'New Horizons' in 2008, then headed to Pluto and Kuiper belt objects located far away from it. Until July 2011 and July 2012, astronomers in turn found these two moons through the Hubble telescope.