According to NASA, the Earth is not a perfect sphere; it's more accurately described as an oblate ellipsoid.
This means the Earth is slightly flattened at its poles and bulging at the equator. The difference between the Earth's equatorial diameter (12,756 km) and its polar diameter (12,714 km) is approximately 42 kilometers (about 26 miles). While this difference exists, it's only about 0.3% of the total diameter, making it visually almost imperceptible.
Why is the Earth an Oblate Ellipsoid?
The Earth's shape is a result of its rotation. As the Earth spins, centrifugal force pushes outward strongest at the equator. This outward force causes the planet to bulge around the equator and flatten at the poles.
Key Differences Explained:
| Feature | Measurement (Approximate) |
|---|---|
| Equatorial Diameter | 12,756 km |
| Polar Diameter | 12,714 km |
| Difference | 42 km |
In summary, while we often visualize the Earth as a sphere, NASA clarifies that its true shape is an oblate ellipsoid due to the effects of its rotation.
