Size and Distance of the Earth, Moon, and Sun PART 1: Size of the Earth Eratosthenes hypothesized that the Earth was a sphere because 1) Sun/Moon are round 2) Earth's shadow appears round during a lunar eclipse. What evidence did Eratosthenes use to support his hypothesis?
1) The Sun and Moon are round
2) The Earth's shadow appears round during a lunar eclipse
3) The Earth is a sphere
4) The Earth's shape is similar to that of other celestial bodies