Differences between the positions from NEP081 and from NEP097. The differences are shown in the orbit radial (R), transverse (T), and out-of-plane (N) directions. These two Triton ephemerides have different orbital models. The model for NEP081 assumes the inner satellites are massless and do not gravitationally attract Triton. The model for NEP097 assumes the orbit of Triton is influenced by the perturbations from the inner regular satellites of Neptune. As NEP081 only provides ephemeris data between 1900 and 2100, we have made the comparison within this time span.