Ecliptic
The ecliptic is the apparent annual path of the sun in the sky, measured from the earth. It forms the basis of the astrological zodiac and indicates the zodiacal area in which the sun, moon and planets are located at any given time.
What is the ecliptic?
The ecliptic refers to the plane in which the Earth orbits the Sun—and thus also the apparent path that the Sun seems to follow across the night sky over the course of a year when observed from Earth. The term derives from the Greek ekleipsis (eclipse), since solar eclipses always occur when the Sun and Moon meet on or near this line.
The ecliptic is the backbone of Western astrology. The twelve signs of the zodiac are arranged along this imaginary line, each covering a 30-degree segment. Since the Moon and planets also move in nearly the same plane, their positions in the horoscope can always be specified in relation to the ecliptic.
The Ecliptic and the Celestial Equator
The ecliptic is tilted by about 23.5 degrees relative to the celestial equator—this angle corresponds to the Earth’s axial tilt and is the reason for our seasons. The two points where the ecliptic and the celestial equator intersect mark the spring and fall equinoxes, which in astrology are defined as the beginning of Aries (0°) and Libra (180°).
If you’d like to learn more about the structure of the astrological system, we recommend our introductory article, Introduction to Astrology.