Full Citation: Kollmeier, J. A., & Raymond, S. N. (2018). Can moons have moons? Monthly Notices of the Royal Astronomical Society: Letters, 483(1), L80L84. https://doi.org/10.1093/mnrasl/sly219
Abstract: Each of the giant planets within the Solar system has large moons but none of these moons have their own moons (which we call submoons). By analogy with studies of moons around short-period exoplanets, we investigate the tidal-dynamical stability of submoons. We find that 10?km-scale submoons can only survive around large (1000?km-scale) moons on wide-separation orbits. Tidal dissipation destabilizes the orbits of submoons around moons that are small or too close to their host planet; this is the case for most of the Solar systems moons. A handful of known moons are, however, capable of hosting long-lived submoons: Saturns moons Titan and Iapetus, Jupiters moon Callisto, and Earths Moon. Based on its inferred mass and orbital separation, the newly discovered exomoon candidate Kepler-1625b-I can in principle host a large submoon, although its stability depends on a number of unknown parameters. We discuss the possible habitability of submoons and the potential for subsubmoons. The existence, or lack thereof, of submoons may yield important constraints on satellite formation and evolution in planetary systems.
URL: https://doi.org/10.1093/mnrasl/sly219