Pluto’s moon Nix was discovered alongside with its other tiny moon Hydra in 2005 using the Hubble Space Telescope. The moons were independently discovered by Max Mutchler and Andres Steffl in the summer of 2005.
The moons were given the provisional designation of S/2005 P1 (Hydra) and S/2005 P2 (Nix), and then later given their permanent names in 2006 by the International Astronomical Union.
Nix is calculated to have a diameter of approximately 46 km if its brightness is the same as Charon, or 137 km if its brightness is same as the darkest objects in the Kuiper Belt. It’s fainter than Hydra, which is why scientists think its smaller in size.
The name “Nix” comes from the Greek goddess of darkness and night; the mother of Charon who was the ferryman that carries souls across the river Styx to the underworld.
Nix will finally be seen up close when NASA’s New Horizons spacecraft finally arrives to image the Pluto system up close in 2015.