Pluto and its large moon, Charon, are at image center. White ovals indicate the orbits of each of the small moons Hubble discovered. Bright, blue-white blobs, and points of light are the individual moons.

Hubble Discovers Four Pluto Moons

Hubble discovered Pluto’s four small moons, Nix, Hydra, Styx, and Kerberos. This is a composite of two images of the Pluto system taken by Hubble in July 2012. The blue areas are from a long exposure used to capture the tiny outer moons, but which greatly oversaturated Pluto and Charon. The dark central vertical band is from a shorter exposure designed to show Pluto and Charon more clearly. The diameters of Pluto and its moons are not to scale.

Credits: NASA, ESA, and M. Showalter (SETI Institute)