A Simplified Model for the Forced Libration of Icy Moons with Subsurface Oceans: Application to Enceladus and Mimas

In this work, we investigate a minimalist model capable of accurately replicating the forced librations of an icy moon with a subsurface ocean. The model holds potential to predict the presence of a subsurface ocean through analysis of longitudinal librations. We demonstrate that a two-layered model, with a prestressed icy crust and a fixed mantle cavity, can effectively model the librational behavior of icy moons. The proposed model is applied to model the longitudinal libration of Enceladus and Mimas, two medium-sized icy moons of Saturn.