Question

5. Why was it necessary to define a new unit to measure distances in the universe? what is
this unit?​

Answer 1

The distances between heavenly bodies in space are very, very large. Measuring these distances in kilometres would mean dealing with very large numbers. Astronomers, therefore, use special units to measure distances in space. Instead of a kilometre, they use a unit called light year.

A light year is the distance that light travels in one year.

Answer 2

The distances measure between heavenly bodies is too large to measure. Measuring these distances in kilometres would mean dealing with very large numbers. Astronomers, therefore, use special units to measure distances in space. Instead of a kilometre, they use a unit called light year