Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721.
Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka 181-8588, Japan.
Proc Natl Acad Sci U S A. 2022 Apr 12;119(15):e2118692119. doi: 10.1073/pnas.2118692119. Epub 2022 Mar 31.
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.
冥王星轨道的许多异常特性被广泛认为是太阳系早期巨行星轨道迁移的证据。然而，一些特性仍然是个谜。冥王星的长期轨道稳定性得到了其轨道的两个特殊性质的支持，这两个性质限制了它近日点的赤经和纬度位置。我们重新审视了冥王星的轨道动力学，以阐明巨行星对限制其近日点位置的个体和集体引力效应。虽然来自海王星的共振摄动解释了冥王星近日点位置的赤经约束，但我们证明，只有在一个狭窄的额外长期稳定的摄动范围内，才有可能出现纬度约束，这是由其他巨行星的特殊轨道结构偶然产生的。我们的研究还发现，木星对冥王星的轨道有很大的稳定影响，而天王星则有很大的不稳定影响。总的来说，冥王星的轨道非常接近强混沌区。
