Our Milky Way Galaxy: How Big is Space?

When we talk about the immensity of the cosmos, it’s easy to toss out big numbers — but far more difficult to wrap our minds around just how large, how far, and how numerous celestial bodies really are.

For instance, to get a better sense of the true distances to exoplanets — planets around other stars — we might start with the theater in which we find them, the Milky Way galaxy.