Moons get treated as afterthoughts in most space coverage, but this film argues they are where the solar system's real action is. It opens with the giant impact that likely created Earth's Moon, then moves to Mars, where Phobos and Deimos sit on doomed orbits that will eventually tear them apart. The bulk of the film settles on Jupiter's four largest moons: Io's constant volcanic eruptions driven by tidal flexing, Ganymede's magnetic field (the only moon known to generate one), and Europa's ice shell, under which instruments have detected a liquid ocean that makes it a candidate for hosting life. Animated flythroughs and simulated flybys stand in for the spacecraft imagery, paired with narration that walks through the physics behind each world's behavior, tidal heating, orbital decay, subsurface chemistry, rather than just listing facts. The throughline is a reframing: these bodies aren't inert satellites but some of the most geologically active and potentially habitable places astronomers have found.