Anyone who teaches about the solar system can’t help but be impressed by the vast array of solar system objects, all of the robotic explorers, and the rapidly evolving view of each object and the systems they inhabit. Far from being a disconcerting jumble of, literally, alien places, the study of the solar system is a perfect example of how science progresses and evolves in the presence of new evidence and analysis. Here are some compelling visual activities (including mathematical computations) that give students an illustration of how empty the solar system is.