Jyotish, referring to jyot, or "light" and "isha", or "lord", is the contemplation of the divinity expressing as time and space. Also known as Vedic astrology, it is the extant form of ancient astrology still practiced in India. Jyotish is the instructional element of the Rig Veda, and as such is a Vedanga, or "body part" of the Vedas. Jyotish is called the Eye of the Veda, for its ability to see into the future. Part of a larger expanse of Vedic studies including mathematics, architecture, medical and military applications, it is the matrix of Western astrology (and the early traces of the descent of various schools of astrology from the Harappan culture, and the Egyptian, Chinese and the Chaldean, through the Arabs, Greeks, and early Romans show complex interweavings being studied by various sects of scholars who presently find little agreement among themselves). Jyotish has many facets, and some of its basics are cornerstones of Western astrology as well, such as the signs and houses, and the names of planets. But Jyotish has a more sophisticated reference to the noumenal: the planets are "grahas", semi-divine consciousnesses that seize created beings and influence their actions and fates. Jyotish is part of a holistic approach to life and spiritual praxis. Its study is a sadhana or technique of mental development referred to in Patanjali's Yoga Sutras. In modern times it is a chief source of reference for many Hindus and other spiritual practitioners across the world. Besides profound commentary on the dilemmas of fate and free will and the philosophy of karma, jyotish includes many remedies for the difficulties found in horoscopes. Vedic astrologers will frequently prescribe special stones, or specific therapeutic practices or meditation techniques using mantras to those facing difficult or unclear futures as predicted by means consistent with Jyotish methodology. In past centuries, Brahmins have been the primary practioners (and, hence, experts for referral) of Jyotish. Since the last century a renaissance of study of Jyotish and other Vedic sciences has been seen in India and the west; currently Indian universities are beginning to sponsor courses in this ancient body of knowledge.
The Vedas, the oldest written texts surviving today, are replete with references to astrology in that cosmology and divinity are indistinguishable from the movements of Nature and planets and the growth of understanding in man as he lives in harmony with his highest spirituality. Surya, the Sun, is a manifestation of Vishnu, a central aspect of the Supreme, and is also the Logos within man. The term "Vedic astrology" has been recently introduced by American and Western astrologers in the 1980s and 1990s, founding groups like the American Council of Vedic Astrology.
Jyotish dates back at least as far as the 3rd millennium BC, and is still commonly used to aid in important decisions in modern India, even by politicians (much as Ronald and Nancy Reagan consulted Western astrologer Joan Quigley ). In Hindu culture, newborns are traditionally named based based on their jyotish charts, and jyotish concepts are pervasive in the organization of the calendar and holidays as well as in many areas of life and science.
Hindu and Western astrologies
The most easily referred to difference between the two lies in the method of measurement of the Zodiac. Vedic astrology uses primarily the sidereal zodiac (the stars are considered to be the fixed background against which the motion of the planets is measured), whereas most Western astrology uses the tropical zodiac (the motion of the planets is measured against the position of the Sun on the Spring equinox). Of course, the ancient rishis were aware of the tropical, season-based cycles of northern and southern declination paths of the Sun and used them also when appropriate. But in the popular mind, the main difference between the two systems is that Jyotish uses the sidereal zodiac and Western astrology uses the tropical. The most obvious effect of the sidereal/tropical difference is that about 80% of planets in a Western chart will move to the previous sign in a sidereal reading of the same chart.
Jyotish pre-dates Western astrology and both have existed for thousands of years. Vedic astrology is uniquely rich and has numerous profound sub-systems of interpretation and prediction incorporating ancient numinous elements not found elsewhere, such as the system of lunar mansions (called nakshatras, presided over by enduring archetypal deities). The nakshatras are used to pick the most auspicious times of day or month for every human activity as well as providing insight into the motivations and guiding characteristics of humans and events coming under their influence. Nakshatra cycles, or dashas, time events with startling accuracy.
Fundamentals of Jyotish
Jyotish is based on what Western astrologers call the whole house system and recognizes nine grahas (heavenly bodies or "planets"):
They also recognize twelve zodiac signs, or Rashis:
One's lagna , or Ascendant, the rashi which is risiing on the eastern horizon at the time of one's birth, is the most influential and important one. Of lesser important but still some impact is the Janma Rashi, the rashi in which the moon lay while one was born.
There are two different Jyotish chart notations, which are functionally equivalent but quite different in appearance. The following images show the same birth chart in both notations.
In the North Indian notation, the house positions are fixed (1st house top middle, with the rest following in counterclockwise order) and the signs of the zodiac are indicated by numbers in the chart (1 for Aries, and so on).
Conversely, in the South Indian notation, the signs of the zodiac have fixed positions (Aries always occupies the 2nd box from the left in the top row, with the rest following in clockwise order), and the first house is marked "As" (for ascendant) with the rest following in clockwise order.
The charts are broken into twelve sections, houses or Bhavas, each of which is related to a rashi in an equal house system .