This fun mechanism is a hand-cranked planetary orrery that shows the first six planets nearest the sun: Mercury, Venus, Earth, Mars, Jupiter and Saturn. This orrery is an adaptation of one that was built for the King of Denmark in 1735, when only six planets were known. I have designed it so that one crank of the handle is equal to one Earth season. Four complete rotations of the crank shows one compete roation of the Earth around the sun and the synchronous movement of the other five planets on their respective orbits. A brief history of this mechanism, which was originally a planetarium installed in the ceiling for the King, and the discovery of the remaining planets is also included in the plan.

The mechanism you see here was built by my friend, Dan Durdle. Dan has built several of my designs and I appreciate his craftsmanship and dedication. Thank you, Dan, for your input.

The open top design, making the internal workings of this mechanism so easily observable is the brainchild of my friend John Tribe. John has chronicled the build of his Copernican Planetary Orrery on his website. He says not only was this a kick to build, but so much fun to crank and watch the planets do their dance through the universe. He tells me that from this he has learned that conjunction of the planets is a very rare event.