The Human Orrery is embedded in the grounds of Armagh Observatory and Planetarium and provides a unique, fun look at planetary motion.
The first orrery was conceived by English clockmaker and inventor George Graham around 300 years ago. This “prototype” only showed the earth-moon system which orbits our Sun. Over the years the model was added to and eventually all the known planets, and some of their moons, were added to the instrument.
Our Human Orrery
Armagh Observatory and Planetarium’s Human Orrery is interactive: it allows people to play the part of the moving planets. It features an accurate scale model of the positions and orbits of the Earth and the five other planets in the Solar System known since ancient times (Mercury, Venus, Mars, Jupiter and Saturn), as well as the asteroid Ceres and two comets: 1P/Halley and 2P/Encke. The orbits of these objects are arranged on the ground with stainless steel tiles.
Jumping from one tile to the next represents a 16 day time interval for all the planets, except Jupiter and Saturn, whose tile jumps represent a 160 day interval. The tiles for Ceres and the comets have 80 day intervals. So choose your celestial body, get interactive and see how long it takes them to orbit our Sun.