FOR CENTURIES, people have wondered if the Earth is round or flat. Sailors and scientists spent years seeking the truth.

Ever since the ancient Greeks first made observations of the circular Moon and the skies, scientists have known that the Earth is a sphere. We’ve all seen beautiful images of the Earth from space, ...

Not quite a sphere Even from space, you wouldn’t detect something important about Earth’s shape: It’s not perfectly round. It’s actually a slightly oblate spheroid, or an ellipsoid. This means it is a ...

WHAT YOU NEED: an orange, pencil and paper. The orange should be as round as possible, so the peel represents the surface area of a sphere. STEP 2: Repeat this 3 more times. You should now have 4 ...