Orrery / noun / or·rer·y
An orrery is a celestial device that shows the positions and motions of planets and stars in the sky. The bodies in the solar system are represented by balls and move by clockwork technology. Orreries vary in size and shape and can be small enough to be hand-held, like a personal globe. Orreries can also be large enough to mount on a life-sized instrument panel.
In a Sentence
The fourth graders were thrilled to see the life-sized orrery when they went to the planetarium on a field trip.
An orrery is a teaching tool that can help us understand the universe.
The physics teacher went in search of a hand-held orrery to use for teaching class.
Etymologists say we derived the word orrery from the Italian word OROLOGIO and the Latin word horologium, meaning "watch." It was first used in English around 1610. There is also some speculation about a model of an orrery being created and named after the Earl of Orrery in the 1800s.
Astrolabe, Astronomical Clock