How Do Scientists Know the Earth Is Round?

Scientists have known for a long time that the Earth isn’t flat. A long time ago, people noticed that ships disappeared below the horizon as they sailed away, like parts of them were being swallowed by the sea! That’s one way to tell the Earth is round. Also, if you go far enough in one direction, you end up back where you started, just like on a ball. Scientists also used the shadow of the Earth during a lunar eclipse, it looked curved, which means the Earth itself must be round too!

Take the quiz →

Examples

  1. A ship disappearing over the horizon looks like it’s falling off a ball.
  2. The shadow on the Moon during an eclipse is round, just like a ball.
  3. If you walk far enough in one direction, you come back to where you started.

Ask a question

See also

Discussion

Recent activity

Nothing here yet.