Zodiac, pronounced ZOH dee ak, is a band-shaped section of the sky that contains 12 special constellations. The zodiac extends about 9 degrees on either side of the ecliptic, the yearly path the sun seems to follow in relation to other stars. The zodiac in astrology. The zodiac has special meaning to people who follow astrology, the belief that the stars and other heavenly bodies influence people's lives. Astrologers divide the zodiac into 12 equal parts called signs, named after the zodiac's 12 constellations. The 12 signs--and the 12 constellations--are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. Astrologers believe that each person comes under the special influence of a particular sign of the zodiac, depending on the date of the person's birth. For example, anyone born from March 21 to April 19 has Aries as his or her sign and is called "an Aries." Astrologers think that people born under each sign have certain characteristics. An Aries, for example, is supposed to be bold, energetic, and strong-willed. However, scientists and many other people consider astrology to be no more than a superstition. The origin of the zodiac. Prehistoric people probably noticed that the seasons changed every year when certain groups of stars reached certain positions in the night sky. These early people may have invented the constellations by giving the groups names that could be represented by human, animal, or other figures. The outlines of the figures, drawn over maps of the night sky, would have helped the people identify and remember the groups. The word zodiac comes from an ancient Greek word meaning circle of animals. Over thousands of years, the constellations have changed their positions in the sky with respect to the celestial equator, an extension of the earth's equator into space. For this reason, people have identified different constellations at different times. According to some historians, the constellations of the zodiac were named in three stages. Gemini, Virgo, Sagittarius, and Pisces were named during the 5000's B.C., when these constellations appeared at the ecliptic in spring, summer, autumn, and winter, respectively. The first farmers in the Middle East may have looked for those four constellations as markers for the change of seasons. By the 2000's B.C., the ancient Egyptians and Mesopotamians had probably identified the constellations Taurus, Leo, Scorpio, and Aquarius as seasonal markers. Aries, Cancer, Libra, and Capricorn may have been added in the 1000's B.C. The earliest known horo-scope to mention all 12 signs of the zodiac dates from about the 400's B.C. The Eastern zodiac, also called the Chinese zodiac, is a set of symbols used since ancient times in China, Japan, Korea, and some other Asian countries. The Eastern zodiac does not involve constellations and has no historical connection with the Western zodiac. Both zodiacs, however, consist of 12 symbols. And in both, according to popular belief, the symbol a person is born under influences the person's character and fate. The 12 symbols of the Eastern zodiac are animals. The zodiac matches the animals to years that repeat in a 12-year cycle. The years 1984 and 1996, for example, were years of the rat. The 12 animals, in chronological order, are the rat, ox, tiger, rabbit (or hare), dragon, snake, horse, sheep, monkey, rooster (or cock), dog, and pig (or boar).