EarthSky – What is an astronomical unit? Astronomical Unit astronomical unit astronomical units Astronomical Unit AU Astronomical Unit distance between the earth and the Sun astronomical units (AU) Astronomical Unit What is an astronomical unit? astronomical units Astronomical Unit Cool Cosmos – Astronomical Unit Astronomical Unit (AU) that of Earth and the Sun නක්ෂත්‍ර ඒකකයක් Astronomical Unit Astronomical Unit that of Earth and the Sun