Discovery: P4, Another Moon Around Pluto
Though 2 percent of astronomers declared Pluto was no longer a planet, for not being a planet, it sure has a lot of moons. Four so far.
The Hubble Space Telescope discovered this fourth moon, cleverly designated P4, and astronomers say this newest, smallest one has an estimated diameter of 8 to 21 miles. By comparison, Charon, Pluto's largest moon, is 648 miles (1,043 km) across, and the other moons, Nix and Hydra, are in the range of 20 to 70 miles in diameter (32 to 113 km).
Distance: 3 billion miles.
The finding is interesting given NASA's New Horizons mission, scheduled to…