“But in the midst of all stands the sun. For who could in this most beautiful temple place
this lamp in another or better place than that from which it can at the same time
illuminate the whole?”
Nicolas Copernicus (1473-1543)3

Astrology interprets the positions of celestial bodies and applies them to life on Earth. In 1507, Copernicus proposed the theory that the Sun, not the Earth, was the center of the Solar System.
Until the Copernicus Theory was accepted, astronomers, who were actually the first astrologers, believed that the universe was both finite, instead of infinite, and that what we now call the Solar System, was geocentric or earth-centered instead of sun-centered1. They believed that the Universe was a celestial sphere with the Earth at its center. As seen from the Earth, the Sun appeared to make a giant orbit, also called the Celestial Circle, around the celestial sphere traveling through the stars and the planets over the course of a year15.

The virtual plane from the Earth to the sun, as the Sun appears to travel along the Celestial Circle, is called the ecliptic and accounts for the formation of the zodiac. During the vernal (spring) and autumnal equinoxes, the Earth intersects the Celestial Circle. The zodiac is based on the apparent positions of the Sun, Moon, planets and stellar constellations as seen from the Earth.
The zodiac divides the ecliptic into twelve equal sections of about 30° each, beginning when the Earth intersects the celestial circle during the vernal equinox. These signs of the zodiac are named after the constellations encompassed in each section and are called "sun signs" or "star signs". An individual's sign is determined by the location of the Sun in relation to the zodiac at the time of his or her birth (see diagram). Each sign represents basic human drives and a set of human characteristics2.
In addition to associating the signs of the zodiac with a season, astrologers associate the
zodiac with the basic elements of fire, air, water, and earth symbolizing their qualities of
heat, cold, dryness and moisture in varying proportions11.