🪐 The History Of The World’s First Planetarium
➥ Hackaday
「 The practical realization of the projector required two independent projection spheres. One projected the stars and moved as a unit. It also held a cage that moved differently with projectors for the planets. Other separate projectors handled things like the Milky Way. There were 180 stars and the orbit of Saturn, just as an example was over 11 meters in diameter 」
