What is the shape of the Earth?

The Earth is best described as an oblate ellipsoid because this shape accounts for the slight flattening at the poles and the bulging at the equator due to its rotation. As the Earth spins, centrifugal force causes the equatorial region to stretch outward, resulting in an equatorial diameter that is slightly larger than the polar diameter. This shape is confirmed by satellite measurements and has important implications for various geographical and physical processes.

The distinction between an oblate ellipsoid and a perfect sphere is significant in fields such as geodesy, navigation, and satellite communication. Understanding the Earth's true shape helps in the accurate representation of geographical data and modeling of various phenomena like gravity variations across the surface.