Orrery

"Professor Trelawney bent down and lifted, from under her chair, a miniature model of the solar system, contained within a glass dome. It was a beautiful thing; each of the moons glimmered in place around the nine planets and the fiery sun, all of them hanging in thin air beneath the glass. Harry watched lazily as Professor Trelawney began to point out the fascinating angle Mars was making to Neptune."

- Harry Potter's Fourth year Divination class

Orreries are models of the sun, planets and moons of the solar system, used for studying Astronomy. Sybill Trelawney used one of all nine planets (including Pluto) while teaching Astrology during Divination in 1995.

Related items

 * During Albus Dumbledore's time as Headmaster of Hogwarts, the Headmaster's office contained a number of orrery-like objects, though their specific purpose is unknown.
 * Globes of the moon and perfect, moving models of the galaxy in a large glass ball could be purchased in Diagon Alley.

Appearances

 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire