Planetarium

Part of speech: noun

Pronunciation: /plænɪˈtɛəɹɪəm/

Definitions

1. An establishment intended for learning about the cosmos, typically featuring a curved ceiling to depict stars and other celestial elements
2. A structure designed for educational purposes that simulates the night sky using a dome to exhibit celestial bodies and astronomical phenomena
3. An facility dedicated to the observation and study of astronomy, often providing dome-like projections of stars and planets for visitors

Etymology: The planetarium is named for the planets, though its most famous feature is the stars. The word was borrowed from New Latin "planetarium", a coinage built from "planet" and the suffix "-arium", a Latin ending used for places associated with a particular thing, as in "aquarium" (a place of water) and "vivarium" (a place of living things). A planetarium, in other words, is literally a place of planets. The reason for the name lies in the machine at its centre. Early planetariums were built around a projector that displayed the moving planets against the dome, so the planets were the show. The stars came along as background, but the name kept its focus on the wanderers of the sky rather than the fixed points of light.

Synonyms: star theater