The ancient Astronomers in India have always been able to accurately predict the occurrence of all astronomical phenomena such as the exact times of solar and lunar eclipses. Even thousands of years ago they knew this science perfectly. They were aware of planets that were not visible to the human eyes. This is because their knowledge is coming from the Vedas, the ancient scriptures of India. They do not depend on their imperfect senses. They get perfect knowledge from the Vedas.