zodiac, in cosmology and soothsaying, a belt around the sky expanding 9° on one or the other side of the ecliptic, the plane of Earth's circle and of the Sun's obvious yearly way. The circles of the Moon and of the key planets additionally lie totally inside the zodiac. The 12 mysterious indications of the zodiac are each considered to involve 1/12 (or 30°) of its extraordinary circle. These signs never again relate to the cosmic heavenly bodies wherein the Sun really shows up. The groups of stars are unpredictable in size and shape, and the Sun consistently goes through one heavenly body (Ophiuchus) that isn't viewed as an individual from the zodiac.
Since the vast majority of the heavenly bodies through which the ecliptic passes address creatures, the antiquated Greeks called its zone zōdiakos kyklos, “circle of creatures,” or ta zōdia, “the little creatures.” The size and number of zodiacal star groupings differed in ancient times and became fixed distinctly with the advancement of numerical cosmology. The rundown underneath gives the heavenly bodies of the zodiac, with the dates of the Sun's section through them in the time when their limits were fixed. These dates are as yet utilized for the celestial signs, however precession of the equinoxes has moved the heavenly bodies toward the east; e.g., on January 1 the bearing of the sun is presently in Sagittarius rather than Capricornus. The historical backdrop of the images is obscure; they appear to show up first in Quite a while of the late Middle Ages.