This is a numerical simulation of the orientation of Nix as seen from the center of the Pluto system. It has been sped up so that one orbit of Nix around Pluto takes 2 seconds instead of 25 days. Large wobbles are visible, and occasionally the pole flips over. This tumbling behavior meets the formal definition of chaos; the orientation of Nix is fundamentally unpredictable.
Credit: STScI and Mark Showalter, SETI Institute
