planetarium (n.)

1734, "orrery, astronomical machine which by the movements of its parts represents the motions and orbits of the planets," Modern Latin, from Late Latin planeta (see planet) + Latin -arium "a place for." Sense of "device for projecting the night sky onto the interior of a dome," developed by Zeiss in Germany, debuted in Munich in 1923 and is attested by the name in English from 1929.