The Twelve Signs of the Zodiac

The twelve signs of the tropical zodiac, Aries through Pisces, divide the ecliptic into twelve equal thirty-degree arcs, each named for the constellation that occupied it in antiquity. Because the tropical zodiac is measured from the moving equinox rather than from the stars, the signs have gradually drifted away from the constellations they are named for, a difference the atlas notes.

Each sign carries an element (fire, earth, air or water), a mode (cardinal, fixed or mutable), a ruling planet, and a body of character and correspondence. Together the four elements and three modes generate the twelve as a systematic set.