Spherical Earth

High school (ages 12+)
Geography

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/spherical-earth

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the early proponents?Pythagoras (philosophical), Aristotle (empirical arguments)
2. What is the first circumference calculation?Eratosthenes (3rd century BC)
3. What clues did ancient Greeks find that showed Earth is a ball?They saw that Earth’s shadow on the Moon during a lunar eclipse is curved, that stars rise higher or lower when you travel north or south, and that ships seem to sink hull‑first as they go over the horizon. These clues showed Earth is round.
4. How did Eratosthenes calculate Earth's circumference?He measured the Sun’s angle at two places at the same time and used the difference to estimate how far around the Earth is. His estimate was surprisingly close to the real size.

Geodetic Datum: A reference system used to accurately measure and represent locations on Earth's surface.
Oblate Spheroid: A sphere that is flattened at the poles and bulges at the equator, like Earth.
Lunar Eclipse: When Earth passes directly between the Sun and the Moon, casting a shadow on the Moon.