Why are there different Zodiacs?
The issue becomes more confusing when you further describe the term ‘zodiac’ with the adjectives ‘sidereal’, ‘tropical’ and ‘constellation’. Why are there different zodiacs? Isn’t there just one belt??
Think of it this way, there is one ecliptic or path that makes up the ‘belt’. However it is the way we divide that path up that creates the different zodiacs.
The issue becomes more confusing when you further describe the term ‘zodiac’ with the adjectives ‘sidereal’, ‘tropical’ and ‘constellation’.Why are there different zodiacs? Isn’t there just one belt?? Isn’t there just one belt??
Think of it this way, there is one ecliptic or path that makes up the belt. However it is the way we divide that path up that creates the different zodiacs.
The Constellation Zodiac
The Sidereal Zodiac
Around the fifth century BCE astrologer-astronomers in Mesopotamia standardized the twelve zodiacal signs so they each measured exactly thirty degrees.Â
Henceforth this path of twelve standardized thirty degree signs was then referred to as the ‘Sidereal Zodiac‘ (from the Latin term sidereus, “of the stars or constellations”).Â
The sidereal zodiac stays (relatively) fixed, it does not move. In fact it is the ‘fixed stars’ (as opposed to the ‘wandering stars’ which refer to the planets) that provide the points that orient the sidereal zodiac.Â
Around the fifth century BCE astrologer-astronomers in Mesopotamia standardized the twelve zodiacal signs so they each measured exactly thirty degrees.Â
Henceforth this path of twelve standardized thirty degree signs was then referred to as the ‘Sidereal Zodiac‘ (from the Latin term sidereus, “of the stars or constellations”).Â
The sidereal zodiac stays (relatively) fixed, it does not move. In fact it is the ‘fixed stars’ (as opposed to the ‘wandering stars’ which refer to the planets) that provide the points that orient the sidereal zodiac.Â
The Tropical Zodiac
Subsequently the tropical zodiac was born out of the ‘discovery’ of the precession of the equinoxes. It is defined by it’s alignment with the earth’s four seasons. 0 degrees Aries begins
precisely at the moment of the vernal equinox (the first day of spring in the northern hemisphere). In particular it was Claudius Ptolemy who was the first Hellenistic Astrologer credited with adopting the tropical zodiac over the sidereal one.
Subsequently the tropical zodiac was born out of the ‘discovery’ of the precession of the equinoxes. It is defined by it’s alignment with the earth’s four seasons. 0 degrees Aries begins precisely at the moment of the vernal equinox (the first day of spring in the northern hemisphere). In particular it was Claudius Ptolemy who
was the first Hellenistic Astrologer credited with adopting the tropical zodiac over the sidereal one.
Similarities and differences between the Tropical and Sidereal Zodiacs
(However, neither  line up exactly with the constellations because the actual constellations are of unequal size. The sidereal zodiac, however, is closer to the original constellation zodiac because it is based on ‘the stars or constellations’ otherwise known as the ‘sidereas’)
Alignment is the main difference between the Tropical and Sidereal Zodiac
- Chiefly the sidereal zodiac is based upon 0º Aries being opposite to the position of the star Spica at the year of 285 AD (Lahiri ayanamsa method.)
- In contrast the tropical zodiac is aligned exactly with the seasons. 0 degrees Aries of the tropical zodiac  begins precisely at the moment of the vernal equinox (the first day of spring in the northern hemisphere).
- Currently difference between the tropical and sidereal zodiacs (known as the ayanamsa) is about 24 degrees. This difference is due to the precession of the equinoxes
(However, neither  line up exactly with the constellations because the actual constellations are of unequal size. The sidereal zodiac, however, is closer to the original constellation zodiac because it is based on ‘the stars or constellations’ otherwise known as the ‘sidereas’)
Alignment is the main difference between the Tropical and Sidereal Zodiac
- Chiefly the sidereal zodiac is based upon 0º Aries being opposite to the position of the star Spica at the year of 285 AD (Lahiri ayanamsa method.)
- In contrast the tropical zodiac is aligned exactly with the seasons. 0 degrees Aries of the tropical zodiac  begins precisely at the moment of the vernal equinox (the first day of spring in the northern hemisphere).
- Currently difference between the tropical and sidereal zodiacs (known as the ayanamsa) is about 24 degrees. This difference is due to the precession of the equinoxes
The sidereal zodiac is used in Vedic Astrology and by some Western Astrologers. The tropical zodiac is typically used by Hellenistic Astrologers and in Western Astrology.
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The sidereal zodiac is used in Vedic Astrology and by some Western Astrologers. The tropical zodiac is typically used by Hellenistic Astrologers and in Western Astrology.
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