Things in space being “xxxx lightyears away”, therefore light from the object would take “xxxx years to reach us on earth”

Question

I don’t really understand it, could someone explain in basic terms?

Are we saying if a star is 120 million lightyears away, light from the star would take 120 million years to reach us? Meaning from the pov of time on earth, the light left the star when the earth was still in its Cretaceous period?

In: 292

Answer 1

Yes. Light travels at approx. 300,000kps. 1 light year is the distance light travels in 1 year. 120 million light years takes light 120 million years to travel.

And it’s from the point of view of the Earth because for the light the journey was instantaneous.