In addition to its large moons, Saturn is attended by what Porco calls “flotsam”—dozens of small, irregularly shaped satellites notable mostly for their spectacular diversity. Among these oddballs are the potato-shaped Prometheus and its cratered neighbors, Epimetheus and Janus.

The smooth, icy surface of Telesto sets it apart from most other Saturnian moons, which are heavily cratered. The surface of Helene appears to have been sandblasted by the many particles swirling around Saturn. Both Telesto and Helene are “Trojan moons” that share their orbits with larger companions.

Spongy Hyperion’s low density suggests that half of its bulk consists of empty space. Phoebe, the largest of Saturn’s irregular moons, circles Saturn in an irregular, backward orbit.