New York State High School Regents Exam Prep
Earth Science

What is the true shape of the Earth and what is the best model of the Earth?

True Shape- Oblate spheriod. This means that the Earth is slightly flattened at the poles and slightly bulging at the Equator.

Best model- a perfectly spherical (round) and smooth object. A bowling ball (without the holes) or a cue ball are excellent examples of models. Don't forget the globe.

Proof of the Earth's shape: Photos from space, changing angle of Polaris above the horizon (altitude), gravity measurements, shadow of the Earth on the moon during a lunar eclipse.

Here are a few things to remember.
Always choose the diagram of the Earth that is the roundest.
The altitude of Polaris is equal to the latitude for any observer in the northern hemisphere.
You will weigh slightly more at the poles because you are closer to the center of the Earth and gravity is slightly greater at the poles than at the Equator.

New York State High School Regents Exam Prep Center: Earth Science