One Astronomical Unit (AU) is the average distance between Earth and the Sun.

An Astronomical Unit is a unit of measurement used in astronomy to represent distances within the solar system. It is defined as the average distance between the Earth and the Sun, which is approximately 149.6 million kilometers or 93 million miles.

The AU provides a convenient scale for measuring distances within our solar system. It is often used to describe the distances between planets, moons, and other objects in relation to the Earth and the Sun. For example, the distance between Mars and the Sun can be described as a certain number of Astronomical Units.

It is worth noting that the distance between the Earth and the Moon is much smaller than an Astronomical Unit, averaging about 384,400 kilometers or 238,900 miles. The distances between other planets and the Sun, such as Jupiter or Pluto, are much greater and are typically described in terms of Astronomical Units.