The Cassini spacecraft has discovered giant structures towering in Saturn's rings. (The spike on the picture is the structure's shadow, not the structure itself.)
In recent weeks, Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons, but also the shadows of newly revealed vertical structures in the rings themselves. And these observations have lent dramatic support to the analysis presented in today's publication that demonstrates how small moons in very narrow gaps can have considerable and complex effects on the edges of their gaps, and that such moons can be smaller than previously believed.
[From Moshe Feder]