This is the story of how our solar system will be transformed by the aging sun before coming to a spectacular end in about eight billion years. Astronomers can peer into the far future to predict how it will happen by analysing distant galaxies, stars and even planets in their final moments. In this film, Horizon brings these predictions to life in a peaceful midwestern town that has a giant scale model of the solar system spread out all over the city. As it ages, the sun will bloat into a red giant star, swallowing planets... as well as half the town. The fate of the Earth itself hangs in the balance. How will the solar system end?