We update the current geodetic models for selected 20 satellites of Saturn on the basis of most recent satellite ephemeris and imaging data from the Cassini mission, which came to its conclusion recently. Specifically, we study the gravitational forcings in the Saturn system and make predictions for rotations of the satellites. Assuming perfect spin-orbit coupling (“resonant rotation”) we derive new reference frame models. Furthermore, we use Cassini image data and block adjustment techniques to measure and update the current rotation parameters for the satellites. Here, the “resonant rotation models” represent important references against which the new measurements are made. We focus on measurements of physical librations for Enceladus, Mimas and Epimetheus, where such measurements may help answer the question for presence of subsurface oceans. Furthermore, we will update satellite shape models and compare these with various equilibrium figures. All results are interpreted in terms of interior structures of the satellites as well as their origins and evolution within the complex Saturn system. Our proposed research will benefit from the complete Cassini data set after end of mission, new powerful block adjustment techniques and internally consistent modeling involving our new geodetic reference frame models.
DFG Programme
Research Grants
