When it first flicked on the projector lights in 1930, the Adler Planetarium in Chicago was the only one in the Western Hemisphere. At the time, planetariums themselves were only a 7-year-old invention imported from German lens grinders. But the American public's fascination with stars and distant worlds, it turned out, was skyrocketing. By 1934, the Adler had welcomed over a million visitors.
