How did the planetarium come to be?
The evolution of the planetarium began when the ancients constructed globes with stars maps painted on their outsides. The Greek mathematician Archimedes is credited for the first one that dates to 250 BC.
The next step was to represent the sky with a hollow sphere. The most famous sphere was the German Gottorp Globe, built in 1664. It was water- powered, three and one half tons, and had a 10-foot diameter. Within it was a platform to accommodate 12 persons. The globe rotated once every 24 hours and its interior showed a map of the sky with gilded stars.
Such spheres were popular for more than 250 years. The last was built in 1913 for the Museum of the Chicago Academy of Sciences. Its Atwood Globe had a 15-foot diameter and electric works. It showed 692 stars, with a moveable light bulb representing the sun. Openings could be uncovered to represent the planets.
Gears and chains and cranks
With advances in instrument making in the 17th century, various mechanical models of the planetary system were constructed as teaching devices. Known as "orreries" for the earl of Orrery (who had them made) they were also called planetariums. Huygens' Planetarium, built in 1682, was the first accurate orrery. You may have had such a model of the Sun, Earth and Moon in your classroom.
The Orrery reached its zenith in the large ceiling orreries, like the Copernican Planetarium (1923) at Munich. This one that had a hanging basket in which a person could ride. The Sun was a nine-inch lighted globe and six planets hung from the ceiling revolving around the Sun by electric motors. Similar mechanisms operated at Morehead Planetarium in Chapel Hill, North Carolina and New York City's Hayden Planetarium.
The First Projection Planetarium
The Orbitoscope was invented in Switzerland, about 1912, by Professor E. Hindermann, and is considered the first projection device for showing planetary motions, but the instrument had many shortcomings. In 1913 the astronomer Max Wolf approached Osker von Miller, cofounder of the Deutches Museum, with the idea for device that would show planetary motions and a realistic star field.
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