The High Definition Earth Viewing (HDEV) experiment aboard the ISS streams real-time images of Earth as seen from low Earth orbit.
A pair of thousand-watt lamps in the star balls of this Zeiss planetarium instrument projected light onto 32 plates. Each was perforated with one hole for every star’s position, plotted from a precise celestial map like the one here and on the wall in front of you. Stars were then projected onto the dome by lenses. Instruments inside the central cage produced the Sun, Moon, and five of the planets.
Throughout history, people devised machines to explain sky motions. The orrery mimicked the planets’ motions as seen from “outside” the solar system. The planetarium projector puts observers “inside” the sky and shows the stars as seen from Earth. Digital systems use video to let viewers explore the cosmos through animations. The Samuel Oschin Planetarium theater has a star projector and a video system to simulate the universe.