An Astronomical Unit (AU) is a unit of length equal to the average distance from the Earth to the Sun, approximately 149.6 million kilometers or 93 million miles.
Examples
**Example:** Jupiter orbits at an average distance of 5.2 AU from the Sun, while Neptune is about 30 AU away. The Voyager 1 spacecraft, launched in 1977, is now over 160 AU from the Sun.