When teaching astronomy at the junior high or college level, how does one explain that Polaris has not always been the pole star? What illustration will best show what is meant by the "circumpolar" stars? Due to the problems of time and distance, few methods are available to help the astronomy instructor. One, however, has proven its worth to some degree and shows great promise for the future. I am referring to the planetarium. This article deals with planetariums such as those listed in the September issue of Sky and Telescope rather than with the small laboratory models sold by some scientific supply companies.
