1. A mechanical model of the solar system that shows the positions and motions of the planets and moons orbiting the sun.
Usage: Named after Charles Boyle, 4th Earl of Orrery, an 18th-century Irish nobleman

Examples

• The museum's orrery demonstrates how Earth and the other planets revolve around the sun.
• Students used an orrery in astronomy class to understand planetary motion.
• The antique orrery in the science center was built in the 1800s and still works perfectly.
• An orrery helps visualize the relative sizes and distances of objects in our solar system.
• The planetarium featured a large brass orrery that rotated to show the positions of all eight planets.