The natural satellites of the giant planets of our Solar System are nearly all locked into resonances. There are spin-orbit resonances, resulting in synchronous rotations as for our Moon, but also orbital resonances between them. This configuration cannot be the result of a random process but is the consequence of slow dissipation acting over the ages, driving the system into a dynamical equilibrium.
Quantifying this dissipation yields clues on the internal structure of these bodies and their parent planets. A good way to quantify this process is to elaborate accurate orbital ephemerides of these bodies, in which this dissipation is considered. For that, we must dispose of the last 100 years of astrometric observations.
In this talk, Dr. Noyelles will explain how the orbital dissipation in Jupiter was quantified, present a surprising result for the Saturnian satellites that could explain the formation of the Cassini Division, and discuss some dynamical aspects of the satellites of Uranus.