# Book:Aristarchus of Samos/On the Sizes and Distances of the Sun and Moon

## Aristarchus of Samos: Περὶ μεγεθῶν καὶ ἀποστημάτων ἡλίου καὶ σελήνης

Published $\text {c.$260$BCE}$.
In English:

On the Sizes and Distances of the Sun and Moon

### Contents

A deduction that the Sun lies about $18$ to $20$ times as far away from Earth as does the Moon.

His method was correct, but his measurements were inaccurate.

The actual value is more like $400$.

However, this was an improvement over the estimate of Eudoxus of Cnidus, who argued for $10$.