The rules of the cosmos change in the deep freeze of the outer solar system, where moons are no longer just dead rocks, but dynamic worlds that challenge our very definition of a planet. In this episode, we journey beyond Jupiter to Saturn’s kingdom, revealing Titan’s toxic atmosphere and methane rivers, and Enceladus, a tiny moon spraying a hidden ocean into space that may contain the ingredients for life. The tour continues to the darker, violent edges of our neighborhood, visiting Uranus’s shattered “Frankenstein moon” Miranda, Neptune’s retrograde ghost world Triton, and the binary dance of Pluto and Charon. From the historic discoveries of Voyager and Cassini to the upcoming Dragonfly mission, discover why these bizarre, icy companions might be the most important worlds we have ever discovered.