The Moon gets pulled out of the picture entirely: this film runs the thought experiment of an Earth that formed without a large satellite and traces the physics forward from there. Scientists explain how the Moon's gravity locks the planet's axial tilt in place, and what happens to that tilt without it, with some models pointing to wilder swings in climate and seasons over geological time. Tides shrink to whatever the Sun alone can pull, reshaping coastlines and the tidal pools some researchers think helped life move from ocean to land. The film also tracks how a moonless sky would have changed human culture, from calendars built on lunar cycles to the mythology and religious symbolism attached to a Moon that never existed. Animations stand in for the missing footage of this alternate Earth, paired with interviews making the case for just how much of the planet's stability, and possibly its biology, depends on a rock formed by a Mars-sized impact billions of years ago.