Resonant Trans-Neptunian Object - Origin

Origin

For details of the evolution of Neptune's orbit, see Nice model.

Detailed analytical and numerical studies of Neptune’s resonances have shown that they are quite "narrow" (i.e. the objects must have a relatively precise range of energy). If the object semi-major axis is outside these narrow ranges, the orbit becomes chaotic, with widely changing orbital elements.

As TNOs were discovered, a substantial (more than 10%) proportion were found to be in 2:3 resonances, far from a random distribution. It is now believed that the objects have been collected from wider distances by sweeping resonances during the migration of Neptune.

Well before the discovery of the first TNO, it was suggested that interaction between giant planets and a massive disk of small particles would, via momentum transfer, make Jupiter migrate inwards while Saturn, Uranus and especially Neptune would migrate outwards. During this relatively short period of time, Neptune’s resonances would be sweeping the space, trapping objects on initially-varying heliocentric orbits into resonance.