A unit of measurement equal to 149.6 million kilometres, the mean distance from the centre of the earth to the centre of the sun.
More example sentences
- Bodies that formed from the Sun out to a distance of about 2.5 astronomical units are primarily rocky and metallic.
- Typical distances from the Sun are 10,000 astronomical units, and typical orbital periods are on the order of 1 million years.
- Today the distance between the Earth and sun, known as an astronomical unit, is accurately measured by radar.
Definition of astronomical unit in:
- The US English dictionary