Question

What method do scientists use to tell how far a galaxy is from earth?

Answer 1

Using a powerful telescope they find some stars which have quality known as standard candles whose brightness in known.in the Galaxy.

Explanation:

This may be a Cepheid variable ot Type ! supernova which can be used as a standard candle.We know the relation ship of dimming of light as per distance Inverse square law,.So distances can be calculated..