by Anura Guruge
On July 18, 2011, NASA scientist using Hubble Telescope images to research the possibility of a faint ring around Pluto discovered a fourth moon — provisionally designated P4. It has an orbit in between that of the other two small moons, Nix and Hydra [page 67 of Devanee’s book.]
Here is NASA’s initial depiction of the orbits — bearing in mind that Pluto and Charon can be thought of as a binary system since Charon does not orbit around Pluto per se, with both orbiting around a common point well outside of the boundaries of both bodies. [page 40].