Other than the fact that Jyotish is designed to fit seamlessly together with Yoga & Ayurveda as we navigate the spiritual process, the most fundamental difference between western astrology and Jyotish is the method of calculating planetary positions:
- In western astrology, the sign of Aries begins where the Earth crosses the vernal equinox (which marks the first day of spring in the northern hemisphere) because western astrology was designed as a calendar to stay in alignment with the cycles of changing seasons.
- In Jyotish, the sign of Aries occupies the same space as the constellation that you can look up and observe in the sky. It measures objects using the Nakshatra based sky, which represents the “spirit” aspect of spirit taking form. Space is the formless, unmanifested, pure essence of nature that’s seeking expression through physical form.
At the time western astrology was implemented, sometime around 500 A.D., the vernal equinox and the constellation of Aries occupied the same section of the sky. However, as time marches forward, the observable sky and the seasonal equinoxes are slowly drifting apart (due to something called “precession”). The current rate of precession is 1 degree every 72 years, and the separation between the equinox and the observable sign of Aries is 24 degrees, almost one full sign. In Jyotish we call this distance the “Ayanamsha”.
In addition to the zodiac calculation, another big difference between western astrology and Jyotish is the timing system. The methods of prediction in western astrology are mainly based on progression, meaning the interaction of planets in the living sky with their placement in the birth chart. While this is relevant and insightful, Jyotish can make highly accurate predictions using the birth chart alone. The placement of the Moon at the time of birth provides a predetermined schedule for certain karmas to ripen (or life lessons to occur). If you picture your life on earth as a day at Universe-ity, the Vimshottari dasa represents your class schedule. This a deeply profound and accurate way of untangling what’s happening in your life and what the planetary professors were/are trying to teach you.
Traditionally, Jyotish uses the “whole sign – whole house” method to determine astrology houses, whereas western astrology mainly divides the area between the Ascendant and the Midheaven, which varies by the latitude of the place of birth. In Vedic philosophy, actions originate from thought, and thought originates from karma, where the house represents the actions, the sign represents the thought, and karma is stored in the planets. To evaluate an outcome, Jyotish will investigate the house/sign and the ruler of that sign in the birth chart to determine whether there’s ease or difficulty in the process of thoughts becoming things.
There are several other strategical differences in chart evaluation, but this covers the main concepts.