Aristarchus of Samos (310 BC – 230 BC), a Greek astronomer and mathematician, created the first known model of the Universe with the Sun at the center and planets in their correct order. Unfortunately he was almost universally ignored until the Renaissance.
He also calculated the relative sizes and distances of the Earth, Moon and Sun. His measurements were not accurate enough to be correct but his method was sound.
Below: 10th century CE Greek copy of Aristarchus of Samos's 2nd century BCE calculations of the relative sizes of the Sun, Moon and the Earth (Vat. gr. 204 fol. 116 recto math06 NS.02).
Aristarchus has a crater on the Moon named after him. In the image below, it's the large crater in the middle.