Eratosthenes estimates Earth’s size
Approximate date · Calendar as reported in the source (not converted) · Date as reported
Eratosthenes used geometrical reasoning to estimate the size of Earth.
- Type
- astronomical observation
- Category
- astronomy measurement
- Organization
- Eratosthenes
- Participants
- Eratosthenes
Sources and attribution
- NASA Goddard — Historical astronomy timeline (opens in a new tab) — Factual summary; source attribution retained.