Question

What are the units which are used to measure distance in space? Explain them briefly.

Answer 1

Following units are used to measure distance in space:

Astronomical unit: Astronomical unit is the mean distance of the centre of the Sun from the centre of the Earth.

1 Astronomical Unit (AU) = 1.496 $\times$ ${10}^{11}$ m

Light year: A Light year is a distance travelled by light in one year in a vacuum.

1 light year = 9.467 $\times$ ${10}^{15}$ m