Pluto’s two newest moons now have official names: Kerberos and Styx, after the three-headed guard dog of the underworld and the river that separates the underworld from Earth, respectively. Previous known as P4 and P5, Kerberos and Styx were the winning names of a contest launched by the SETI Institute. Fun fact: the top winning name was actually Vulcan (thanks to a campaign launched by William Shatner), however the name is already in use and the Roman god is not closely associated with Pluto. Despite our love of science fiction, we astronomers like to be self-consistent whenever possible.
After the jump, a nice graphic to put Pluto and its moons in perspective…(via Space.com)