Neptune's moon, Triton, orbits close to Neptune in a circular orbit. However, it orbits in the opposite direction of Neptune's other inner moons. The simulation triton.gsim shows Triton in its retrograde orbit. The initial starting conditions were obtained using data from JPL's Horizons Ephemeris Computation Service.

Download triton.gsim

(You need to have the program Gravity Simulator installed on your computer first. Click Here to download Gravity Simulator.)