Question

Define a) Astronomical unit b) Light year
[2 Marks]

Answer 1

a) An Astronomical Unit (AU) is the average distance between Earth and the Sun, which is about 93 million miles or 150 million kilometers.
[1 Mark]

b) Light year is a unit of length in astronomy equal to the distance that light travels in one year in a vacuum or about 5.88 trillion miles or 9.46 trillion kilometers
[1 Mark]