Following completion of the ring orbits, Cassini will perform unprecedented dives between Saturn and its rings between April and September. Then, on September 15, Cassini will make a suicidal plunge into Saturn itself to protect icy worlds like Enceladus from the small chance of Cassini crashing into and contaminating their surfaces.
But before that, Showalter points out, Cassini will provide more insights on what is happening within the Uranus system, even though the spacecraft is surveying a completely different planet. The wobbles in Saturn's narrow rings appear to move in similar ways that Uranian rings do, for example.
But there are still several mysteries that may take another Uranian mission to resolve.
For example, images from Voyager 2 depicted dust rings surrounding the main ring system of. Then, when Uranus reached its equinox (closest point in its orbit) in 2008, observations from the Keck Telescope imaged the rings when they were edge-on from Earth, making it easier to identify the presence of any dust. It appears that the dust has shifted 3,100 miles between the two observations, Showalter said. The reason for the shift remains poorly understood.