Hyperion and Tethys
Cassini had close encounters with two moons of Saturn in the last week and the photos are coming in. The moons are very different and the photos are very amazing.
Here's a full frame view of Tethys, but the false color closeup is what seems really alien. (Flyby distance: 310 miles)
This full frame view of Hyperion shows a bizarre, spongy looking surface, but what puzzles Top Men is the dark material in the bottom of the craters. Also check out NASA's Hyperion flyby movie. (Flyby distance: 930 miles)