Mechanical planetaria were already known in ancient Greece,

though the planetary orbits with their loops, that the Ptolemaic world model constructed

around a stationary earth at its centre, most likely cannot have been replicated mechanically.

The most famous example is the Antikythera mechanism, discovered in a shipwreck, which was much like a calculating machine.

It is said that Archimedes, too, was able to demonstrate mechanically the orbits of the Sun and Moon.

Almost all of the mechanical planetaria we know are based on the ideas of Nicolaus Copernicus (1473 -1543),

who regarded the Sun as the centre of the world.

He proclaimed that the Earth does not remain in place but rather moves in three ways:

1. it revolves once in 24 hours

2. it orbits around the Sun once per year on a circular path

3. it turns its axis in such a way that it always points in the same direction and not towards the Sun.

Despite heavy resistance from the church, this world model continued to spread and,

through improvements made by numerous scientists, evolved into the generally accepted scientific world model of today.

One of these scientists was Johannes Kepler, who discovered the elliptical nature of the planetary orbits.

At the beginhing of the 18th century the Earl of Orrery and other English aristocrats asked watchmakers to manufacture

crank-driven mechanical models of the planets, which are called orreries since that time.

One of the largest and most famous movable planetariums was built; by the Frisian Eise Eisinga in the years 1774 to 1781

in the town of Franeker; where it is still exhibited.

Today the, name "planetarium" is mostly used for projection planetariums like those that were first constructed by

the Zeiss optical company in Germany at the beginning of the last century.

These project the stars onto the inside of a large dome.

The AstroMedia* Copernicus Planetarium stands in the tradition of the mechanical, crank-driven planetary models

that are exhibited by selected museums as masterpieces of the watchmaking and precision engineering arts.

Its simple drive belt design, the robust cardboard construction and the affordability of an assembly kit

make this interesting and instructive device available to a larger public once again.

Things Needed For Assembly:

Check the website link for further information...