The Andromeda Galaxy is 2.5 million light-years from our solar system and is the closest spiral galaxy to us. It probably looks a lot like our own Milky Way. There’s probably also some dork taking a picture of us at the same time I was taking this picture of them. Of course, the ...
Using Gaia data [3], the motion of M31 relative to the Milky Way was determined using a significantly improved method than previously, confirming that the two massive galaxies are infalling toward their first close encounter. Other related properties of M31, in addition to various measures of ...