The average distance from Earth to the Sun is 1 AU or 150 million kilometers. An Astronomical Unit is a unit of measurement that scientists use to describe distances within our solar system.It is based on the average distance between the Earth and the Sun, which is about 150 million kilometers (or 93 million miles).Instead of saying “150 million kilometers” all the time, scientists say “1 AU.” For example:Earth - 1 AU from the Sun.Mars - about 1.5 AU from the Sun.Jupiter - about 5.2 AU from the Sun.