What are the distances between planets measured in?
Depends on the distance. Generally, it’s either kilometres or AU. Light years would be much, much too large — it only takes light a matter of minutes to reach anything in the inner solar system… even Pluto gets its light relatively quickly, less than six hours. Measuring the solar system in light years would be like measuring the floor space of your home in square miles. AU = the distance between earth and the sun, so it’s used to measure the distance to far away planets (the outer solar system — Jupiter, Saturn, Uranus and Neptune). Usually we measure the distance to planets with the inner solar system (Mercury, Venus and Mars) with kilometres, as well as the distance to the moon and various debris near Earth. When doing calculations, a person will usually convert the distances into whatever units are easiest to work into their calculations.
