Caption: A diagram from 10th century CE Greek copy of Aristarchus of Samos' (c.310--c.230 BCE) treatise On the Sizes and Distances of the Sun and Moon (3rd Century BCE).

Aristarchus did NOT arrive at accurate values---his geometry was strong, his instruments were weak.

Later ancient Greek astronomers finally got a fairly accurate distance to the Moon of ∼ 60 Earth radii (No-102).

But the ancient Greek astronomers never got any other astronomical distances accurately.

Aristarchus and Seleucus of Seleucia (fl. 150 BCE) were the only two people before Nicolaus Copernicus (1473--1543) known to have advocated heliocentrism---but almost nothing is known about their version of heliocentrism---we just have bare statements that they advocated it.

Ironically, On the Sizes and Distances of the Sun and Moon (3rd Century BCE) assumes a geocentric solar system model.

Credit/Permission: Aristarchus of Samos (c.310--c.230 BCE), 3rd century BCE (uploaded to Wikimedia Commons by User:Konstable, 2006) / Public domain.
Image link: Wikimedia Commons: File:Aristarchus working.jpg.
Local file: local link: aristarchos_manuscript.html.
File: Ancient Astronomy file: aristarchos_manuscript.html.