Yardsticks are very useful around the house when you need a measurement. (I have also used them to fish out toys the cat knocked under a low piece of furniture.) They are standards by which we can ...

In 1925, Edwin Hubble's observation of Cepheid variables in the Andromeda galaxy revolutionized astronomy, proving the ...

How is astronomical distance determined? Just cannot get my head around cepheid variables, parallax, etc. How is it possible to tell how far away something is when you cannot bounce a radar beam off ...

One common misconception of beginner sky watchers is that we can tell the distances of the stars by just looking at them. In fact, you might be surprised to learn that the opposite is often true.

Answer: For near stars, astronomers use a method called parallax. During Earth’s orbit, near stars seem to shift their position against the farther stars. This is called parallax shift. By observing ...