New moon

A new moon has been discovered accidentally by astronomers using the Hubble Space Telescope.  The moon, temporarily named P4, orbits the dwarf planet Pluto.  It is the smallest of Pluto's moons, with an estimated diameter of 8-21 miles.  P4 is located between the orbits of Nix and Hydra, Pluto's second- and third-largest moons.

NASA is planning a mission to fly through the Pluto system in 2015.