It seems a long way to go for a simple answer, but the Cassini R-4 Rhea Flyby slated for Saturday morning (shortly after ten, Pacific Time) is just one of the many simple answers sought by scientists studying the Saturnian system. And that simplicity, in a way, is a striking reminder of what humanity can achieve.
This gravity flyby is designed to understand the internal structure of Saturn’s second largest moon. Is Rhea a homogeneous body or did it differentiate into a core, mantle, and crust like the Earth? The radio science subsystem will use radio waves beamed to Earth to perform precise measurements designed to answer this question.