In astrology as well as astronomy, the ZODIAC is a 360° circle around the earth, where each of the twelve Zodiac signs is 30°. In astronomy it is simply used as a coordinate system, to mark the positions of celestial bodies. In astrology, though, it is much more. In astrology each Zodiac sign represents a character, a tendency, which affects any celestial body therein. Every planet that moves through the Zodiac, changes character according to what sign it is in.