The Dendera zodiac is an ancient bas-relief temple ceiling carved with mysterious symbols of stars and planets. During Napoleon’s Egyptian campaign (1798-1801), French scientists discovered the zodiac in the ceiling of a small chapel atop a temple outside the town of Dendera, near Thebes. Made of sandstone and weighing many tons, the zodiac excited immense wonder and admiration, for it seemed to open a window onto a civilization of almost immeasurable antiquity.
The zodiac is a planisphere or map of the stars on a plane projection, showing the 12 constellations of the zodiacal band forming 36 decans of ten days each, and the planets. These decans are groups of first-magnitude stars. These were used in the ancient Egyptian calendar, which was based on lunar cycles of around 30 days and on the heliacal rising of the star Sothis (Sirius).
Its representation of the zodiac in circular form is unique in ancient Egyptian art.More typical are the rectangular zodiacs which decorate the same temple’s pronaos.
The celestial arch is represented by a disc held up by four pillars of the sky in the form of women, between which are inserted falcon-headed spirits. On the first ring 36 spirits symbolize the 360 days of the Egyptian year.
On an inner circle, one finds constellations, showing the signs of the zodiac. Some of these are represented in the same Greco-Roman iconographic forms as their familiar counterparts (e.g. the Ram, Taurus, Scorpio, and Capricorn, albeit most in odd orientations in comparison to the conventions of ancient Greece and later Arabic-Western developments), whilst others are shown in a more Egyptian form: Aquarius is represented as the flood god Hapy, holding two vases which gush water.