The Belt of the Heavens
The zodiac is the circular band of sky about 16° wide through which the Sun, Moon, and all classical planets move as seen from Earth. It is divided into twelve signs of 30° each, named after the constellations that once occupied those positions. Every planet's sign placement is defined by where it falls within this belt. Western astrology uses a tropical zodiac fixed to the seasons; Vedic astrology uses the sidereal zodiac fixed to the stars.
The Twelve Signs
| Sign | Element | Modality | Ruler |
|---|---|---|---|
| Aries | Fire | Cardinal | Mars |
| Taurus | Earth | Fixed | Venus |
| Gemini | Air | Mutable | Mercury |
| Cancer | Water | Cardinal | Moon |
| Leo | Fire | Fixed | Sun |
| Virgo | Earth | Mutable | Mercury |
| Libra | Air | Cardinal | Venus |
| Scorpio | Water | Fixed | Mars/Pluto |
| Sagittarius | Fire | Mutable | Jupiter |
| Capricorn | Earth | Cardinal | Saturn |
| Aquarius | Air | Fixed | Saturn/Uranus |
| Pisces | Water | Mutable | Jupiter/Neptune |
Tropical vs. Sidereal Zodiac
The tropical zodiac begins Aries at the vernal equinox fixed to Earth's seasons. The sidereal zodiac aligns signs with the actual star positions, differing from tropical by roughly 23–24° (the ayanamsa). A person with Sun in Aries tropically may be Pisces in sidereal. Western astrologers use tropical; Vedic astrologers use sidereal. The choice of zodiac fundamentally changes every sign placement and must be stated when discussing planetary positions.