Astronomical Unit
The mean distance from Earth to the Sun — exactly 149,597,870,700 metres.
Definition
An astronomical unit (AU or au) is defined as exactly 149,597,870,700 metres. It was originally defined as the mean Earth–Sun distance. It is the standard unit for distances within our solar system.
Formula
1 AU = 149,597,870,700 m ≈ 1.496 × 10¹¹ m
Examples
- Mars is about 1.52 AU from the Sun.
- The outer edge of the Oort Cloud is estimated at 100,000 AU from the Sun.