Combining optical and radio science data of JUICE and Europa Clipper missions to constrain the ephemerides of Io

The dissipative mechanisms in the Jovian system play a key role in the evolution of mean-motion resonances among Jupiter’s satellites. Tidal dissipation is the main driver behind the formation and long-term maintenance of the Laplace resonance involving Io, Europa, Ganymede, and indirectly Callisto. This resonance sustains Io’s volcanic activity and helps preserve the possibility of subsurface oceans on Europa and Ganymede. The upcoming JUICE and Europa Clipper missions will explore the Jovian system through numerous close flybys, providing extremely precise radio tracking data. These measurements will significantly improve the determination of the moons’ gravity fields and ephemerides, allowing the estimation of their tidal parameters and those of Jupiter, expressed through the imaginary part of its degree-2 Love number. However, neither mission will fly close to Io, the moon that most strongly interacts tidally with Jupiter. Its tidal properties can still be inferred through its dynamical coupling with the other Galilean moons, but with larger uncertainties compared to the other bodies. The goal of this project is to investigate the integration of simulated optical observables (focused on Io moon) into a multi-arc covariance analysis that already includes radio tracking data from JUICE and Europa Clipper, using NASA/JPL’s MONTE orbit determination software. The study will define optical measurement characteristics (observation epochs, uncertainties, and correlations) and propose scheduling strategies to combine them with existing radio data. Simulations will test different optical observation configurations, both for each mission independently and for a combined analysis. The objective is to assess the capability of optical data to complement radio tracking and reduce uncertainties in Io's ephemerides and tidal parameters.