Astronomical Unit

The astronomical unit for length is described as the “mean” distance (average of aphelion and perihelion distances) between the Earth and the Sun. Though most references state the value for 1 AU to be approximately 150 million kilometers, the currently accepted precise value for the AU is 149,597,870.66 km.

The time required for light to travel from the sun to the Earth is approximately 8 minutes and 20 seconds.

Symbol:  au, ua, or AU