NASA has released some pretty astonishing pictures from Cassini, but this is one of the best: A flyby picture of Saturn's icy moon Dione:
The thin band you can see near the bottom of the screen is the ballyhooed rings of Saturn. Because the probe is travelling near the equator of Saturn, the rings are seen edge-on. But if you look in the upper right, you can see the shadows that the rings cast.
Way to go NASA. I know this isn't the reason we support space exploration, but it kind of is.