Hey Ray! The Shape Of The Earth

PITTSBURGH (KDKA) -- Standing on Earth and looking out, the Earth looks flat from our very limited view.

We know the Earth isn't flat, though. Did you know Earth isn't a perfect sphere either?

When you see a globe or other representation of Earth, it usually is shown as a perfect sphere, so many people may think that it is.

The Earth, though, is what we call an Oblate Spheroid.

It is a sphere, just smooshed down a bit, and is a little fatter in the middle.

There are different forces that change Earth's shape from a sphere to an oblate spheroid.

One of them is gravity. If gravity were the only force giving our planet shape, it would be a sphere since gravity is pulling from all directions toward the center.

Earth's rotation gives us the other force.

As things rotate, Earth included, there's an apparent outward force. We call that centrifugal force.

This gives our planet a situation where gravity is pulling inward, but the rotation causes it to spin outward, too.

These fighting forces causes the north and south poles to flatten a bit, and the equator to bulge, giving Earth its shape.

An oblate spheroid.