Era of Vedic astrology
It is very difficult to say that when did the astrology started. This science is considered the most ancient and is included in ancient epics. This science was recited by the gods, hence it is known as divine science. It is also known as Vedang or Pratyaksh Shastra. India is the only country where this science has been developed and has been explored since ancient times.
The sages and saints of India have taught us to achieve Brahma Gyana through practising Yoga and by awakening of Kundalini. The spread of knowledge in ancient days was through transmission of ideas from one person to another. The leaves of copper were used for writing in those days and everyone who had this knowledge was not able to use it for preserving the knowledge of astrology. The hereditary transmission of this knowledge from a father to a sun or from a mentor to protege was the only medium to preserve this knowledge.
Vedic Astrology of Vedic Era
From 10,000 B.C.. onwards, Vedic era started in which jyotish was one of the six vedangas. The Vedas may have been written around 5000B.C.In Four Vedas references are clearly available to show that even during those times, people were aware of the orbits of planets, seasons, ayanas, yugas, days, months, adhik and akshay tritiya, eclipses during that time.
Rig Veda the oldest veda refers to 12 lunar months in a year.Poornima and amavasya find mention. Ritus and uttarayana and dakshinayana are explained and well known.The rising,setting and combustion of planets and 12 zodiac signs were known in that period.Yajurveda describes 27 nakshatras. Athaeveda describes about propitiations to be performed for the child born in gandmool nakshatra.It give attention to the janma nakshatra in the form of tara vichar which is still practiced today.
Astrology was significant in Vedic era. At that time astrologers analyze the motion of the Sun, Moon, Mars, Mercury, Jupiter,Venus, Saturn and Nakshatras. They also calculated the duration of a day, the duration of a night, duration of a year.
Astrology was used for finding Muhurtas to perform auspicious rites. The auspiciousness of the time is also taken into consideration while performing religious or routine work. The people of Vedic era were fully acquainted with Nakshatras. They fixed the equinox point in the last stage of Bharani Nakshatra. It is now taken from the beginning of Kritika nakshatra.
Astrologers of Vedic era knew the names of the Nakshatras and the method of calculating their stages. They also knew how to nominate the lords of these Nakshatras. All the account of the development of astrology in Vedic Era are based on observations had become so advanced in those days is amazing.The creators of siddhantas were Gods and not humans.They were Surya, Soma,Brihaspati, Narad and Brahma.
With the advancement in writing of books, the spread of knowledge helped in systemic growth.500 B.C to 1000 B.C can be truly called development era of hindu astrology.!8 siddhantas were given by great astrologers.However varahamihira considered only five siddhantas.
Ever since the Vedic times, the knowledge of Indian astronomy grew gradually and was at its peak in the Medieval period.It was all by mere observation and calculations, although the variations still were very small which reflect the knowledge in ancient times.