How do we know that distance between earth and sun is 1 astronomical unit ?

1 Answer
Dec 19, 2015

The Astronomical Unit (AU) is based on the average distance of the Earth from the Sun.


The Astronomical Unit was defined to be the average of the Earth's perihelion distance and its aphelion distance.

The Astronomical Unit has since become an international SI unit and has an exact value of 149,597,870.7 meters.