The zodiac is the circle of twelve 30° divisions of celestial longitude employed by western astrology and (formerly) astronomy. The western zodiac is centered upon the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets also remain close to the ecliptic, within the belt of the zodiac, which extends 8-9° north or south of the ecliptic, as measured in celestial latitude. Because the divisions are regular, they do not correspond exactly to the boundaries of the twelve constellations after which they are named.