Since its arrival on July 1st of 2004, the Cassini spacecraft has revealed an astonishing and complex picture of the Saturnian system. Among the unexpected results are the high activity of Enceladus, a very rich and complex ring structure, and the internal ocean of Titan. Some of the satellites have unexpectedly high eccentricities, geologically young surfaces and active interiors. The mutual interactions between Saturn, its satellites and the rings determine the evolutionary history leading to its current dynamical configuration.
More recently, another spacecraft, the Juno mission, has visited the Jovian system. This mission is going to provide the community with the best gravity field of Jupiter, with significant consequences for the improvement of orbital models of the moons. Simultaneously, HST observations confirmed, in 2016, large geysers at the Europa surface reminding us of the Enceladus geysers.
It is generally admitted that tidal dissipation is the most likely mechanism for both changing the orbits and heating the synchronously rotating satellites. The angular momentum transfer within a planetary system is associated with the possible resurfacing rate of the satellites as well as with the dynamical configuration and resonances. For Saturn and Jupiter, several satellites are in mean motion orbital resonances such as the pairs Dione and Enceladus, Mimas and Tethys, and the three innermost Galilean moons Io, Europa and Ganymede. The undamped eccentricities and inclinations of the satellites can be due to past or present resonances. These systems raise several open questions such as the origin of mechanisms of satellite resurfacing, coherent scenarios for capture into resonance for different pairs of satellites and, for Saturn, the initial state of the rings. All these questions motivate global dynamical studies that take into account the tidal interactions and secular variations of the orbital parameters.
Our international team is composed of experts from different fields related to planetary sciences (including astrometry of the Solar system objects, orbital and rotational dynamics, physics of tidal dissipation in planetary and stellar interiors). This association of experts from diverse specialties proved its efficiency with high ranked articles in the past few years. Both Cassini and Juno missions will end in the coming years. Hence, it is the perfect time to settle (until the next space mission) scenarios of formation and evolution, while extending our research to the Jovian system to prepare the upcoming missions: EMFM (ex Europa clipper) and JUICE.