On July 29, 2011, the unending dance of Saturn's moons lined them up perfectly for a stunning view by the Cassini spacecraft: five moons arrayed for your pleasure:
[Click to embiggen.] From left to right that's Janus, Pandora (in the rings), Enceladus, Mimas, and Rhea. Perspective plays a role here; Rhea is three times bigger than Enceladus, but was much closer to Cassini when this picture was taken, so it looks even bigger. But the moons themselves are so different from each other! Janus is a lump, too small to have enough gravity to crush itself into a sphere. Enceladus is mostly ice, so it appears very bright in this image compared to its rocky siblings. You can just barely see part of the monster crater Herschel peeking out of the dark side of Mimas, while Rhea is peppered with smaller craters. And Pandora orbits inside Saturn's rings themselves, its ...
