Definition of astronomical unit in US English:
astronomical unit
(also AU)
nounˈˌæstrəˈnɑməkəl ˈjunət
Astronomy A unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.
〔天文〕天文单位
Example sentencesExamples
- These stars are generally separated by distances of several astronomical units or more.
- Because the relative distances to the planets were well known, a definitive astronomical unit allowed the actual distances to be calculated.
- 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.
- Bodies that formed from the Sun out to a distance of about 2.5 astronomical units are primarily rocky and metallic.
- Even at its closest, Sedna comes no nearer to the Sun than 76 astronomical units, each AU equaling the average distance of the Earth from the Sun.