Nautical Mile to Astronomical Unit Converter

A nautical mile is a unit of length used in navigation, equal to exactly 1,852 meters or approximately 1.151 statute miles. It is based on the Earth's circumference and is defined as one arc minute of latitude.

The nautical mile originated from the need for a unit of distance that related to the Earth's geometry for navigation purposes. It was historically defined as one minute of arc along a meridian of the Earth. The international nautical mile was standardized at exactly 1,852 meters in 1929.

Nautical miles are universally used in maritime and aviation navigation worldwide. They're the standard unit for measuring distances at sea, flight distances, territorial waters, and exclusive economic zones. Speed in nautical miles per hour is called a knot.

An astronomical unit (AU) is a unit of length approximately equal to the average distance from Earth to the Sun, defined as exactly 149,597,870.7 kilometers or about 93 million miles.

The astronomical unit was originally defined as the semi-major axis of Earth's orbit around the Sun. It was first estimated by Giovanni Cassini in 1672 and has been refined over centuries. In 2012, the International Astronomical Union redefined it as an exact value rather than a measured quantity.

Astronomical units are primarily used for measuring distances within the solar system, including distances between planets, asteroids, and comets. They're standard in planetary science, space mission planning, and solar system astronomy.