Nix was found by the Hubble Space Telescope Pluto Companion Search Team, composed of Hal A. Weaver, Alan Stern, Max J. Mutchler, Andrew J. Steffl, Marc W. Buie, William J. Merline, John R. Spencer, Eliot F. Young, and Leslie A. Young.
The formal name "Nix", from the Greek goddess of darkness and night and mother of Charon (ferryman of Hades), was announced on 21 June 2006 on IAU Circular 8723,[REF] where the designation Pluto II is also given.