Making Models

Strange things have been known to happen on quiet country roads. Travelers on New Mexico highway 6563, for example, blaze past the planets of the solar system at more than 10 times the speed of light.
Or, to be more precise, they pass road signs with the names of the planets. The signs correspond to the scale of the solar system, radiating from a model of the Sun at the Sunspot Observatory. At that scale, traveling at highway speeds is like warping through space with the U.S.S. Enterprise.
Big models of the solar system have been built at many sites in the United States and other countries. They serve as tourist attractions, but they also help people understand the vast distances between planets.
There’s one in Peoria, Illinois, for example, that’s centered on a 46-foot disk of the Sun at a science museum. And one in Midland County, Michigan, is built along a historic trail.
The biggest one in the U.S. stretches 40 miles across Maine. In that model, one mile equals the distance from Ea