The last Vedanga Jyotisha is called eye – the organ of sight, of the Veda Purusha. The object of Jyotisha Vedanga is not to teach astronomy, but to convey such knowledge of the heavenly bodies as is necessary for fixing the days and hours of the Vedic sacrifices. It gives some rules for calculating and fixing time for sacrifices. In the Brahmanas and Aranyakas, we find frequent allusions to astronomical subjects, and even in the hymns we find traces which indicate a certain advance in the observation of the moon.It is unfortunate that there is no work available at present dealing with ancient Vedic astronomy (Jyotisha) in the Sutra style. Only we have a small text-book called Jyotisha of Vedic astronomy in verses in two recessions. Generally, Maharshi Lagadha is regarded author of this Vedanga Jyotisha. This is a very difficult text and, therefore, is not clear on several points to scholars even today. Later, we find many Sanskrit treatises on astronomy and mathematical calculations. Bhaskaracharya, Varahamihira and Aryabhatta are known ancient scholars conversant with these scientific subjects. The principles established by them are in use in the modern world.