mean motion resonance

Mean motion resonance is the dynamical situation where the ratio of the orbital periods of two orbiting objects can be expressed as the ratio of two small integers. For example, plutinos are Kuiper Belt objects that are in a 3:2 resonance with Neptune, meaning that they orbit twice in the time Neptune completes three orbits. Mean motion resonances may lead to major changes in the orbit of one or both of the bodies or may enhance orbital stability, depending on the precise nature of the resonance.