Planetarium

A planetarium is a theatre built for presenting shows about the night sky. They typically use a large inverted bowl shape for the projection screen, with a number of movable cameras projecting the image of a star or planet onto the screen. Additional projectors add in backgrounds like trees and hills, or special events like comets.

The term can also be used to describe the projector itself, or other devices to illustrate the solar system, like an orrery.