Zodiac

The zodiac is the band of sky, extending roughly 8 degrees on either side of the ecliptic, through which the Sun, Moon, and all the planets of our solar system appear to travel over the course of a year, because they all orbit the Sun in nearly the same flat, disk-shaped plane. This band passes through 13 official constellations recognized by modern astronomy — Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Ophiuchus, Sagittarius, Capricornus, Aquarius, and Pisces — though traditional astrology, which developed thousands of years ago from the same underlying astronomical pattern, generally recognizes only 12 signs and does not include Ophiuchus. It's important to distinguish the zodiac as a genuine astronomical fact, the real region of sky where solar system objects travel, from astrology, which assigns predictive or personality-based meaning to a person's zodiac sign and has no basis in physical science. Astronomically, the zodiac remains genuinely useful: because planets are always found somewhere within this band, it tells observers exactly where in the sky to look for them, and ancient astronomers' careful tracking of planetary motion through the zodiac constellations was foundational to the historical development of astronomy as a science.