Three-body resonances in the Saturnian system

M Ćuk, M El Moutamid - The Astrophysical Journal Letters, 2022 - iopscience.iop.org
The Astrophysical Journal Letters, 2022iopscience.iop.org
Saturn has a dynamically rich satellite system, which includes at least three orbital
resonances between three pairs of moons: Mimas–Tethys 4: 2, Enceladus–Dione 2: 1, and
Titan–Hyperion 4: 3 mean-motion resonances. Studies of the orbital history of Saturn's
moons usually assume that their past dynamics was also dominated solely by two-body
resonances. Using direct numerical integrations, we find that three-body resonances among
Saturnian satellites were quite common in the past, and could result in a relatively long-term …
Abstract
Saturn has a dynamically rich satellite system, which includes at least three orbital resonances between three pairs of moons: Mimas–Tethys 4: 2, Enceladus–Dione 2: 1, and Titan–Hyperion 4: 3 mean-motion resonances. Studies of the orbital history of Saturn's moons usually assume that their past dynamics was also dominated solely by two-body resonances. Using direct numerical integrations, we find that three-body resonances among Saturnian satellites were quite common in the past, and could result in a relatively long-term, but finite capture time (10 Myr or longer). We find that these three-body resonances are invariably of the eccentricity type and do not appear to affect the moons' inclinations. While some three-body resonances are located close to two-body resonances (but involve the orbital precession of the third body), others are isolated, with no two-body arguments being near resonance. We conclude that future studies of the system's past must take full account of three-body resonances, which have been overlooked in the past work.
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