Natural satellites ephemerides

Abstract

Since Galileo Galilei’s first discovery of natural satellites orbiting around other planets, observing and reconstructing their dynamics has been at the core of our efforts to understand and characterise these distant worlds. Far from following perfect, frozen in time Keplerian orbits, the dynamics of these satellites keep evolving, with tides as driving mechanism. The dissipation of energy in natural bodies due to their visco-elastic response to tidal forcing both heats up the moons’ interiors and causes their orbits to expand or shrink, as well as to become more circular or elliptical. Refining the moons’ ephemerides (i.e., tabulated solutions of their motion as a function of time) is thus key to studying not only their present-day dynamics, but also the long-termthermal-orbital evolution of planetary systems....