Pluto near the edge of chaos

TL;DR

This paper investigates Pluto's orbital stability, revealing that its near-chaotic orbit is maintained by a delicate balance of gravitational influences from the giant planets, with some effects stabilizing and others destabilizing.

Contribution

The study clarifies how specific gravitational interactions from giant planets collectively influence Pluto's orbital constraints and stability near the edge of chaos.

Findings

Neptune's resonant perturbations constrain Pluto's azimuthal perihelion location.

A narrow range of secular forcing from other planets maintains Pluto's latitudinal perihelion constraint.

Jupiter stabilizes, Uranus destabilizes Pluto's orbit.

Abstract

Many of the unusual properties of Pluto's orbit are widely accepted as evidence for the orbital migration of the giant planets in early solar system history. However, some properties remain an enigma. Pluto's long term orbital stability is supported by two special properties of its orbit that limit the location of its perihelion in azimuth and in latitude. We revisit Pluto's orbital dynamics with a view to elucidating the individual and collective gravitational effects of the giant planets on constraining its perihelion location. While the resonant perturbations from Neptune account for the azimuthal constraint on Pluto's perihelion location, we demonstrate that the long term and steady persistence of the latitudinal constraint is possible only in a narrow range of additional secular forcing which arises fortuitously from the particular orbital architecture of the other giant planets. Our investigations also find that Jupiter has a largely stabilizing influence whereas Uranus has a largely destabilizing influence on Pluto's orbit. Overall, Pluto's orbit is rather surprisingly close to a zone of strong chaos.