How is the size of a galaxy measured?

1 Answer
Mar 9, 2016

In light years for actual measured distance. In the red shift for its age and the distance light has traveled.


The actual size of our universe is somewhat in question. That is because of the limitations of our present technology to "see" and measure objects, galaxies, stars, at the furthest reaches of our universe. But in general, light years and astronomical units (AU) for objects within our solar system.