Orrery
mechanical model of the solar system
An orrery is a mechanical model of the Solar System. It shows the relative positions and motions of the planets and moons. It is usually a heliocentric model.[1]
![](http://up.wiki.x.io/wikipedia/commons/thumb/8/88/Orrery_small.jpg/350px-Orrery_small.jpg)
The Greeks had working planetaria. The first orrery that was a planetarium of the modern era was produced in 1704.[2] One was presented to Charles Boyle, 4th Earl of Orrery – hence the name. They are usually driven by a clockwork mechanism. The globe in the centre represents the Sun, and a planet is at the end of each arm.
The first known orrery was the Antikythera mechanism, variously dated from 60 to 150 BC.
References
change- ↑ King, Henry C. & Millburn, John R. 1978. Geared to the stars : the evolution of planetariums, orreries, and astronomical clocks. Toronto: University of Toronto Press. pp. 28–41. ISBN 0-8020-2312-6
- ↑ Calvert, H.R. 1967. Astronomy: globes, orreries and other models. London: H.M.S.O.