Estimation of the Ephemerides and Gravity Fields of the Galilean Moons Through Orbit Determination of the JUICE Mission

摘要

Jupiter and its moons are a complex dynamical system that include several phenomena like tides interactions, moon’s librations and resonances. One of the most interesting characteristics of the Jovian system is the presence of the Laplace resonance, where the orbital periods of Ganymede, Europa and Io maintain a 4:2:1 ratio, respectively. It is interesting to study the role of the Laplace resonance in the dynamic of the system, especially regarding the dissipative nature of the tidal interaction between Jupiter and its closest moon, Io. The secular orbital evolution of the Galilean satellites, and so the Laplace resonance, is strongly influenced by the tidal interaction between Jupiter and its moons, especially with Io. Numerous theories have been proposed regarding this topic, but they disagree about the amount of dissipation of the system, therefore about the magnitude and the direction of the evolution of the system, mainly because of the lack of experimental data. The future ESA JUICE space mission is a great opportunity to solve this dispute. The data that will be collect during the mission will have an exceptional accuracy, allowing to investigate several aspects of the dynamics the system and possibly the evolution of Laplace Resonance of the Galilean moons. This work will focus on the gravity estimation and orbit reconstruction of the Galilean satellites by precise orbit determination of the JUICE mission during the Jovian orbital phase using radiometric data.