Insights from Formation Scenarios into the Internal Differentiation of the Galilean Moons

The internal differentiation of the Galilean moons remains an open question. Gravity data from the Galileo mission indicate that Callisto's interior is only partially differentiated, while magnetic field observations suggest the presence of a subsurface ocean. Similarly, recent reanalysis of Galileo data challenges the longstanding assumption of a metallic core in Europa. 

Estimates of the temperature distribution within the growing satellites, combined with the dynamics of liquid water and the sedimentation of rock particles, could provide insights into the development of the internal structures of the present-day Jovian moons. We compute the thermal evolution of the interiors including radiogenic heating, accretional heating from multiple impacts, tidal heating, and heating from the surrounding circumplanetary disk environment.

We investigate the most plausible internal structures of the Galilean moons by combining observational data with multiple formation scenarios. Specifically, we address the paradox of Callisto's subsurface ocean coexisting with its cold interior and explore the conditions that could facilitate iron melting and the formation of a metallic core in Europa and Ganymede. Furthermore, we examine the debated hypothesis of the existence of a primordial ocean on Io.