Many modern discoveries about the sun, moon, and planets turn out to have been known facts in ancient times. In my books, I have pointed out that not only did our very ancient ancestors have accurate measurements of the diameter of the Earth, Moon, and Sun - and distance to the Sun and Moon - but that Eratosthenes gave us an obviously FAKE explanation of how he came up with some of the answers. Since his explanations were impossible, and we know he was the third curator in charge of the Library of Alexandria, we must assume that great hidden knowledge was available within its scrolls, and that he was forbidden from openly explaining the truth.