Zodiac, an imaginary belt in the heavens, extending 9° N. and 9° S. of the ecliptic, within which the motions of the sun, moon, and principal planets are confined. It was divided by the ancients into 12 parts of 30° each, designated and indicated by arbitrary signs as follows: Aries, the Ram, ; Taurus, the Bull,; Gemini, the Twins, II; Cancer, the Crab,; Leo, the Lion, i; Virgo, the Virgin,; Libra, the Scales, =; Scorpio, the Scorpion, Sagittarius, the Archer,; Capricornus, the Sea Goat,; Aquarius, the Water-Bearer, ; and Pisces, the Fishes, These names were given from a fanciful resemblance to the objects designated which was supposed to be presented by the configuration of the stars. This division is still employed. The width of the zodiac was originally determined by the widest range of planetary motion N. and S. of the ecliptic, for Venus is at times nearly 9° N. of the ecliptic and at times nearly 9° S. of that circle. If the motions of the planets between Mars and Jupiter were considered, the zodiac would have to be nearly 70° wide instead of 18°, and would cover much more than half of the celestial sphere.