The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty Images A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known ...

Through the early 1900s, astronomers disagreed on whether the universe was home to a multitude of galaxies, so-called “island universes,” or contained entirely within the boundaries of the Milky Way ...

If we could go back 101 years, we would encounter a time when scientists still thought the Milky Way was the entirety of our ...

Chris Impey does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...

This article was originally featured on The Conversation. A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical ...