Ryan Dahoumane | Searcharxiv

arXiv2026

Dynamically favorable hosts for submoons around Jupiter and Saturn

The long-term stability of small bodies orbiting natural satellites (submoons) in the Solar System has been previously investigated using an analytical approximation of a three-body problem, focusing mainly on tidal forces and neglecting other perturbations. This approach suggests that submoons around most of the regular satellites in the Solar System could be stable. However, no such object has been detected to date. In this work, we extend these previous results by numerically testing the survival of submoons around a large number of satellites of Jupiter and Saturn. Our goal is to rank the satellites of Jupiter and Saturn according to how dynamically favorable they are for submoon survival over the simulated timescales. For each regular or irregular satellite considered, we performed 130 separate N-body integrations, each containing one hypothetical submoon with a different initial semimajor axis and inclination. From the 1 Myr survival fractions, we rank the satellites according to their dynamical favorability for submoon survival over the simulated timescale. We find that, after 1 Myr, the satellites with the highest survival fractions (above 30%) are Iapetus ($\approx 37\%$), Titan ($\approx 35\%$), Rhea ($\approx 32\%$), Phoebe ($30\%$), Callisto ($\approx 34\%$), and Ganymede ($30\%$). Rather than providing absolute probabilities for the existence of submoons, these survival fractions identify the most dynamically favorable hosts. Iapetus, Titan, Rhea, Phoebe, Callisto, and Ganymede are the most dynamically favorable submoon hosts among the tested satellites.

astro-ph.EP↗

arXiv2025

Origin of Phobos and Deimos : Orbital evolution shortly after formation from a potential dislocation

This paper deals with the formation and evolution of Mars' moons, Phobos and Deimos, assuming the dislocation of a larger progenitor as the origin of these moons. The study by Hyodo et al. (2022) argue that under somewhat simplistic modeling, the post-dislocation orbits of Phobos and Deimos inevitably collide within 10,000 years, leading to their mutual annihilation. These findings are based on $\mathcal{N}$-body simulations, accounting for Mars' $J_2$ and $J_4$ gravitational perturbations and mutual perturbations between the moons. In this paper, we challenge these findings by extending their work. We incorporate important perturbations such as solar perturbations, Mars' axial precession and nutation, and its deformation along three axes. We also extend some of the hypotheses made by Hyodo et al. (2022) concerning the initial distribution of Phobos and Deimos after the dislocation. Our analysis reveals that including these additional perturbations as well as the possibility of having more than two fragments after the dislocation does not alter the ultimate fate of Phobos and Deimos. The moons still converge towards collision within comparable timescales, supporting Hyodo et al. (2022) conclusions that the dislocation hypothesis under the dynamical scenario developed by Bagheri et al. (2021) has, in the best conditions, about 10\% chance of surviving after the first 100,000 years following their formation.

astro-ph.EP↗