Earth Polar Radius
The Earth's polar radius is the distance from the center of the Earth to the North or South Pole. It measures the Earth’s radius along its rotational axis.
Its value is approximately 6,356.8 kilometers (about 3,949.9 miles).
The Earth is an oblate spheroid, so the polar radius is slightly shorter than the equatorial radius due to the planet's flattening at the poles.
This measurement is crucial for geodesy, understanding Earth’s shape, and satellite navigation.
Key facts:
Polar radius ≈ 6,356.8 km
Smaller than equatorial radius by about 21.3 km
Important for precise Earth modeling and mapping
The difference between the polar and equatorial radius reflects the Earth’s rotation and its effect on the planet’s shape.
Light Year
A light year is a unit of distance used in astronomy to measure how far light travels in one year. Light moves extremely fast—about 299,792 kilometers per second—so in one year, it travels roughly 9.46 trillion kilometers (or about 5.88 trillion miles). Light years help scientists express the huge distances between stars and galaxies. For example, the nearest star to Earth, Proxima Centauri, is about 4.24 light years away. The term “light year” can be confusing because it sounds like a measure of time, but it actually measures distance.
No conversions available for length.