Source: World News Australia

Two newly discovered moons orbiting the last known planet in our solar system, Pluto, have been officially named as Nix and Hydra.

Christened at the International Astronomical Union (IAU), the body in charge of approving celestial names, the names were chosen by their discoverers, led by Alan Stern of the Southwest Research Institute in Boulder, Colorado in the United States.

Until now, the duo had been known by an uninspiring combination of letters and numbers – S/2005 P 2 and S/2005 P 1.

Mr Stern says that their new names, were partly chosen because their first letters “N� and “H� matched the initials of the New Horizons spacecraft, as a tribute to the spacecraft which blasted off earlier this year on a nine year mission to study Pluto.

But the names also have their roots in Greek mythology. Nix, originally spelt Nyx but changed because a near Earth object already had that spelling, is named after the Greek goddess of darkness. Hydra gets its name from a nine headed serpent that guarded the underworld. And they’re in good company – Pluto is named after the Roman God of the Underworld and its first discovered moon Charon is the Greek ferryman of the dead.

This northern summer, the IAU will debate if Pluto should remain classified as a planet. Its future became unclear after the discovery of an icy object slightly larger than it in the Kupiter Belt. The IAU will discuss whether to demote Pluto or add other planets.