Long thought to be Andromeda, we're now finding out the Milky Way might have a chance at being number one. When we hold these two galaxies up against one another, comparing our own Milky Way to Andromeda, we find there are some stark differences that suggest Andromeda is the more dominant of the two. In other words, even though the stars tell a different story, the overall mass shows that the Milky Way is likely as massive as the most massive estimates for Andromeda. For a very long time, our observations of Andromeda and the Milky Way seemed to indicate that we were second to Andromeda in pretty much every way as far as our local neighborhood was concerned. It's very much possible that our Milky Way is as massive or even more massive than Andromeda.

Source: Forbes March 14, 2019 06:00 UTC