From immemorial times, watching the heavens has provided inspiration for mankind. Astrology is perhaps the most ancient arcane system of cosmic wisdom that links all life, creation, the universe and man to 12 houses, 9 planets, 12 signs made by Lord Vishwakarma at the order of Lord Shiva. Jyotisha (Sanskrit: ज्योतिष, IAST: Jyotiṣa) is the science of tracking and predicting the movements of astronomical bodies in order to keep time. It refers to one of the six ancient Vedangas, or ancillary science connected with the Vedas – the scriptures of Hinduism.This field of study was concerned with fixing the days and hours of Vedic rituals.
Astronomy and astrology are intertwined; call them the twin sisters acknowledged by our ancient ancestors. Astronomy provides the foundation and structure from which astrology springs. Right from what Zodiac is, revolution of all planets, their speed, rotation , degrees of rise, set all are take in account in astrologer's predictions.
There is a hung jury when we try to define astrology. Many say it is an art of divination. Others insist that it is only pure science. And the controversy goes on unresolved without offering a definitive answer. But Indian Vedic scripture has an absolute answer to it. The ancient extant text on Jyotisha is the Vedanga-Jyotisha, which exists in two editions, one linked to Rigveda and other to Yajurveda. The Rigveda version consists of 36 verses, while the Yajurveda recension has 43 verses of which 29 verses are borrowed from the Rigveda.
We argue that it is both a science and an art. The scientific portion of astrology comes into play as we work with the astronomical, mathematical, and geometrical methods. Astrology is based on observation and correlation both in a scientific and divinatory manner. The ancients watched the sky, observing the movements of planets and other heavenly objects, recorded them and were then able to make quite accurate predictions as to their future appearances. That's science at work.
They also began to observe when specific heavenly orbs in certain positions would correspond to changes in weather or events in their lives. This 'omen' divination was the earliest use of astrology.
So in a nutshell, astrology is the oldest system of a universal wisdom for self-knowledge and awareness as well as divination using natural phenomenon.