Nautical Mile (UK)
The nautical mile (UK) is a unit of distance used primarily in maritime and aviation navigation in the United Kingdom. Traditionally, it was defined as 6,080 feet (about 1,853 meters), which is slightly longer than the modern international nautical mile of 1,852 meters. This UK definition was used before international standardization in 1929. Today, the international nautical mile is widely adopted, but the UK nautical mile historically played an important role in navigation and mapping.
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.