Aryabhatta
476 BC-550 BC India
Aryabhata was the first astronomer to make an attempt at measuring the Earth's circumference since Eratosthenes (circa 200 BC). Aryabhata accurately calculated the Earth's circumference as 24,835 miles, which was only 0.2% smaller than the actual value of 24,902 miles. This approximation remained the most accurate for over a thousand years.
