Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v1.c2.1

v1.c2.1

In the remote past, when man first appeared on this planet, he would have looked with awe and wonder at the glory of the heavenly bodies like the sun, the moon and the stars. He would not have failed to notice that these bodies kept moving across the sky. However, centuries must have rolled by before some inquisitive and careful observers could discover that there was some periodicity in the movement of these heavenly bodies and such a rhythmic movement could be utilised to reckon time and to keep a count of the days and the months in the year. This was the beginning of Astronomy, which is one of the earliest sciences ever to be discovered in the history of mankind. When and where exactly this occurred, or it occurred at several places independently of each other, it is difficult to say now, because the early man did not have with him any means of keeping a record of his thoughts and observations. In India, which is one of the oldest civilizations in the world, we get evidence of astronomical observations as early as 4000 B. C. in the verses of the Rig-Veda and in some developed form later in the Yajur-Veda. As early as 1300 B. C. the Hindus developed a luni-solar calendar known as the Vedanga Jyotisa Calendar. This was in vogue upto the third century A. D. Thereafter, astronomy in our country took a sharp turn and a new system based on scientific principles called the Siddhantic system came into prominence. This development which continued upto the 12th century A. D. came to a standstill due to continued foreign invasions thereafter. The great epics, the Ramayana and the Mahabharata, contain some astronomical knowledge in a rather rudimentary form. Puranas which are works of a later period contain astronomical knowledge in an improved form, apparently due to the influence of the Siddhantic system of Astronomy.