Dynamical stability in the vicinity of Saturnian small moons. The cases of Aegaeon, Methone, Anthe and Pallene

TL;DR

This study investigates the orbital stability of particles near Saturn's small moons Aegaeon, Methone, Anthe, and Pallene, revealing that particles in resonances can remain stable for thousands of years if moons are massless, but are destabilized within hundreds of years when moons are massive.

Contribution

The paper provides a detailed numerical analysis of the dynamical stability near small Saturnian moons, including the effects of moon mass on particle orbital stability and arc erosion timescales.

Findings

Massless particles in resonances remain stable for at least 10^4 years.

Massive moons cause significant perturbations, destabilizing particles within hundreds of years.

Initial arcs around moons are eroded on similar timescales, constraining gravitational influence durations.

Abstract

In this work we analyze the orbital evolution and the dynamical stability in the vicinity of the small Saturnian moons Aegaeon, Methone, Anthe and Pallene. We numerically resolve the exact equations of motions to investigate the orbital motion of thousands of test particles within and near to the domain of the 7/6, 14/15, 10/11 mean motion resonances of Aegaeon, Methone and Anthe with Mimas, respectively. We show that, for massless small moons, the orbits of particles initially restricted to the resonant domains remain stable for at least $10^4$ yr. We also conduct numerical simulations considering Aegaeon, Methone, Anthe and Pallene as massive bodies. The results show that most particles undergo significant perturbations in their orbital motions, ultimately destabilizing in timescales of a few hundreds of years or even less through collisions with the four small moons. In addition, we also simulate the orbital evolution of test particles initially distributed in form of arc around Aegaeon, Methone and Anthe. We show that the initial arcs are dynamically eroded on timescales of hundreds of years, allowing us to constraint the timescales for which gravitational forces operate to remove particles from the observed arcs.