Inside the 75-foot dome, many New Yorkers saw, for the first time, all of the stars visible to the unaided eye, as well as the Sun, Moon, planets, and our spiral galaxy, the Milky Way.
“No dweller in cities has ever seen the stars in such splendor,” read a report from The New York Times. “Out of nothingness the heavens, with their seeming myriads of stars, spring into view as though one had been a privileged witness to their very creation.”
Those “seeming myriads of stars”—4,500, to be exact—were cast on the darkened dome by what the Times called a “strange, ‘man-from-Mars’ contraption”: the Zeiss projector. Though it was no 10-bit color video projector like the model used today, at the time it was one of the most cutting-edge projection instruments.
By sending light through “lantern slides”—in this case, pieces of copper foil punched with tiny round holes—the Zeiss filled the planetarium with dazzling stars and constellations. On each copper slide, the holes varied in size depending on the brightness of the star represented. The faintest stars were shown using holes as small as one-thousandth of an inch. It may sound rudimentary, but the projector was surprisingly precise: it could display the orbiting motions of the Sun, Moon, and planets with a margin of error of less than 1 percent.
Over the course of the next decade, as the equipment was upgraded, New Yorkers would see auroras, eclipses of the Sun, and dramatic thunderstorms—complete with streaks of lightning—in the planetarium dome. Some of the first space shows—like The Trip to the Moon, The End of the World, Mysterious Mars, and Why the Weather?—opened during this time. Nearly 80 years later, the Museum is still bringing audiences the latest science about our cosmos.
Come back every Friday for more images from the Hayden Planetarium archives. We’ve uncovered some incredible astronomical art, vintage photos, and retro posters that we can’t wait to share.