The Copernican Orrery A world premiere: the first ever fully functional cardboard orrery! It demonstrates the movements of Mercury, Venus, Earth and Moon around the Sun. One turn of the crank represents one week and shows the relative movements of the heavenly bodies accurately. The 4.5 cm measuring illuminated sun in the centre helps demonstrating the seasons, phases of Moon and Venus, eclipses, and much more. A fantastic kit that never fails to impress!