Astronomical Unit

This article is a stub. You can help Marspedia by expanding it.

An Astronomical Unit (AU) is most often used to measure distances within the Solar System. One astronomical unit is approximately the distance between the Earth and the Sun but is defined as exactly 150 million km (150'000'000 km).

For example Mars is about 2.5 AU from the Sun, which means it is 2.5 times the distance from the Earth to the Sun, or approximately 375 million km from the Sun (i.e. 150'000'000 km * 2.5).