Astrology & the Heavens

This section covers Western astrology and the celestial framework it is built on: the seven classical planets, the twelve signs of the tropical zodiac, the decans and fixed stars, the twelve houses, the aspects between planets, the Arabic parts, the three hundred and sixty Sabian symbols and the phases of the Moon.

The system is Hellenistic in its mature form, assembled in the Greek-speaking Mediterranean of the first centuries CE, but it rests on much older Babylonian astronomy and celestial omen-reading, and it was transmitted onward through the Arabic world and medieval Europe, gathering material at every stage.

A birth chart in this tradition is a map of the sky at a moment of time, and its meaning is read from how the parts combine. The signs divide the ecliptic into twelve equal arcs; the houses divide the local sky by the daily rotation of the earth; the planets are placed in both, and the aspects measure the angles between them. Finer divisions (the thirty-six decans, the individual fixed stars, the calculated Arabic parts and the degree-by-degree Sabian symbols), are overlaid on that frame.

This section treats the tropical, equinox-based zodiac of the Western tradition. The sidereal, star-based astrology of India is a separate system with its own logic and is gathered under Vedic Astrology, and the Chinese and East Asian systems under Eastern Systems.