"In India the first references to astronomy are to be found in the Rig Veda which is compiled around 6000 B.C. Vedic Indians in fact deified the Sun, Stars and Comets. Astronomy was then interwoven with astrology and since ancient times. Indians have involved the planets " (called Grahas) with the determination of human fortunes (They calculated the forces each Grahas applied on earth and on one another at the time of birth and thus derived the effect of each graha). The planets Shani, i.e. Saturn and Mangal i.e. Mars were considered inauspicious. They calculated the radius of earth and Eclipses"
The following two articles give a glimse of Ancient Indian Astronomy. They had the idea that Sun is also a star. They knew how to calculate area of a triangle and sphere. They knew about the gravitaional force. They made close approaches to the concept of Helicentrism.....
Please go ahead and read the following two articles.
The Àryabhatíya of Àryabhata, The oldest exact astronomic constant? © 1998 by James Q. Jacobs
Ancient India's Contribution to Astronomy -Sudhir Birodkar
The Speed Of Light And The Meaning Of 108 -Professor Subhash Kak (narrated by Linda Johnson)