Create a scale model of the solar system with this lesson plan from NASA and the Stanford Solar Center. The lesson begins with an exploration of model cars. Then, students estimate which objects to use to create a scale model of the Sun and Earth. Students learn how to figure out how far to place the model Earth from the model Sun to create a distance that is in scale with the objects. Students also see what the rest of the planets would look like in the same scale model. Optional extension activities allow students to see where the planetary orbits would be in the model; additional worksheets have students explore the relative sizes of the nearest star, our galaxy, and the universe.