How is distance measured in astronomical units?

1 Answer
Dec 31, 2015

1 AU is the distance from the Sun to the Earth.


1 Astronomical Unit is taken as the Standard distance from the Sun to the Earth which is also the Semi-major axis of the Earth's orbit around the Sun, roughly equal to 1.5 million km.

So, for larger distances it is preferred to use AU instead of km and for even larger distances we have Light-years and Parsecs respectively.