The Zodiac

There are many different forms of astrology and many different ways of interpreting a chart. But at least all Western astrologers agree on something as basic as the Zodiac. Don't they? If only it was that simple...

What Is The Zodiac?

The Zodiac is in effect a map of the heavens on which the positions of the planets can be plotted. An imaginary band around the Earth is extended outwards along the plane of the ecliptic through which (more or less) the planets rotate.

Zodiac Chart
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This band is then divided into a number of sections, each of which is named after one of the stellar constellations. As the Earth and the planets move, the apparent location of each planet within the Zodiac changes over time. Since the Earth revolves around the Sun, the Sun appears to move through the Zodiac regularly throughout the year. The apparent movement of some of the other heavenly bodies is less simple.

Unfortunately, there is more than one Zodiac! The two main Zodiacs in Western astrology are the tropical and the sidereal. Of these, the tropical Zodiac is the one most frequently used in the US and Europe. When we tell people our Star Sign we are usually talking in relation to the tropical zodiac.

Tropical vs Sidereal

In essence, the tropical Zodiac is a mathematical construct that calculates the signs in accordance with the seasons of the year whereas the sidereal Zodiac looks at the actual position of the constellations in the sky. About two and a half thousand years ago, when the tropical Zodiac was fixed, these two were the same. Since then the precession of the equinoxes has meant that they have drifted apart.

According to the tropical Zodiac, the annual parade of signs begins with the sign of Aries at the vernal equinox (first day of spring) in the Northern hemisphere. In the sidereal Zodiac Aries begins when the Sun actually enters the constellation's assigned area of sky - the vernal equinox currently falls in Pisces according to this system.

The sidereal Zodiac can thus be argued as more "real" than the tropical one, however the majority of Western astrologers in the US and Europe continue to use the tropical system. There are a relatively small number of strong supporters of the sidereal system.

What Are The Signs of The Zodiac?

If astrologers disagree over which Zodiac to use, at least they agree on the twelve signs of the Zodiac. Don't they?

Er, not all of them. Some like to include little known constellations such as Ophiuchus. However it's fair to say that the vast majority of Western astrologers use the familiar system of twelve signs:

Sign		Tropical Dates	Element	Modality
Aries	The Ram	Mar 21 - Apr 20	Fire	Cardinal
Taurus	The Bull	Apr 21 - May 21	Earth	Fixed
Gemini	The Twins	May 22 - Jun 21	Air	Mutable
Cancer	The Crab	Jun 22 - Jul 22	Water	Cardinal
Leo	The Lion	Jul 23 - Aug 22	Fire	Fixed
Virgo	The Virgin	Aug 23 - Sep 22	Earth	Mutable
Libra	The Scales	Sep 23 - Oct 23	Air	Cardinal
Scorpio	The Scorpion	Oct 24 - Nov 22	Water	Fixed
Sagittarius	The Archer	Nov 23 - Dec 22	Fire	Mutable
Capricorn	The Goat	Dec 23 - Jan 20	Earth	Cardinal
Aquarius	The Water Carrier	Jan 21 - Feb 19	Air	Fixed
Pisces	The Fish	Feb 20 - Mar 20	Water	Mutable

(Note that the dates can vary slightly depending on exact year, time and location; dates near the changeover between signs are known as being on the "cusp").

The sign that contained the Sun when you were born is called your "Sun sign" - this is the sign you look up when reading your daily horoscope.