Light travels a distance of 9,460,528,000,000 km in a single year, and this makes the definition of the speed of light. This distance is used to measure gigantic objects in the Universe that are far away from us and can’t be measured regularly. 

There are 63000 astronomical units in one light-year and 63000 inches in one mile and this is a phenomenal coincidence that has enabled us to bring the light-year down to Earth.

The closest star system to Earth after the sun is called Alpha Centauri and it is 4.4 light years away.

What do we know about Alpha Centauri?

Alpha Centauri is actually a triple star system that viewed from Earth looks just like a single star. It is the third brightest star visible from Earth. The two main components of it are Alpha Centauri A and Alpha Centauri B. The third star is called Proxima Centauri and it's the closest star to the sun.

For more information, the formula and other conversions you can use our free Length Converter.