Text Box: The Surya Siddhanta,   A textbook on astronomy of ancient India, last compiled in 1000 BC, believed to be handed down from 3000 BC by aid of complex mnemonic recital methods still known today.   Showed the Earth's diameter to be 7,840 miles, compared to modern measurements of 7,926.7 miles.   Showed the distance between the Earth and the Moon as 253,000 miles, Compared to modern measurements of 252,710 miles.