​​How do we measure the distances to things in space?

There are a few primary methods used to measure distances to objects in space:

Parallax:For relatively nearby objects within our own galaxy, we can use the parallax effect. This involves measuring the apparent shift in position of an object against the background as observed from two different locations (such as the Earth at different times of the year). The degree of parallax shift is inversely proportional to the distance.

Redshift:For distant galaxies and other extragalactic objects, we can use the redshift of their light to estimate their distance. As objects move away from us, their light is shifted towards longer, redder wavelengths, and the degree of redshift is proportional to the recession velocity, which is in turn related to the distance via Hubble's law.

Standard Candles: Astronomers can use "standard candles" - objects of known intrinsic brightness, like certain types of stars or supernovae. B...