Question

Briefly explain importance of light year​

Answer 1

Measuring in light-years also allows astronomers to determine how far back in time they are viewing. Because light takes time to travel to our eyes, everything we view in the night sky has already happened. In other words, when you observe something 1 light-year away, you see it as it appeared exactly one year ago.

Answer 2

Light-year is the distance light travels in one year.

Step-by-step explanation:

Measuring in light-years also allows astronomers to determine how far back in time they are viewing. Because light takes time to travel to our eyes, everything we view in the night sky has already happened.