Uranus and its complex and unexpected system of moons are still today a mystery of the solar system. This thesis focuses on the dynamics of these natural satellites, and discusses their orbital and internal evolutions, in the future as in the past. These motions are strongly perturbed by the orbital mean motion resonances; in particular, the 3:1 resonance is present at several places in the Uranian system and is one of the keys to understand its complexity. In this work, a model of resonance (truncated and averaged) is proposed, based on the restricted 3-body problem; it is compared with a numerical full N-body model. Those models are applied to the satellites Cressida and Desdemona, both close to the 3:1 resonance with Miranda. Coupled with the tidal and oblateness effects, they propose, for the first time, a dynamical scenario for the two satellites, in agreement with the present observations. The same resonance appears between the huge moons Miranda and Umbriel; Miranda is characterized by a surprising high inclination, explained by several authors in the nineties, by a past temporary capture in a secondary resonance. The results of this thesis, based on recent methods of chaos detection, numerical integration and frequency analysis, have confirmed, nuanced and completed this explanation. Again for Miranda, an innovative interdisciplinary approach is developed, which couples the orbital and thermal evolutions and gives promising results.
|la date de réponse||14 avr. 2014|
|Superviseur||Anne Lemaitre (Promoteur), Timoteo Carletti (Président), BENOIT NOYELLES (Jury), Alain Vienne (Jury), B. Sicardy (Jury) & Rudolf Dvorak (Jury)|