What is the difference between an AU, light year, and parsec? When should each be used?
1 Answer
Jan 2, 2016
An AU is 150 million kilometers or 93 million miles, a light year is 10 trillion kilometers and a parsec is 3 light years.
Explanation:
1 AU is the distance between the Sun and the Earth so it should be used to define distances of the planets. The nearest star to us is 4.2 light years away and light year should be used to define distances of the stars and finally, parsec should be used to define distance of nebulae etc.
