Crash of the Galactic Titans: Milky Way & Andromeda Collision in ~4 Billion Years FriendsofNASA.org: In about 4 billion years, the Milky Way and Andromeda galaxies will collide. The three largest galaxies in our Local Group of Galaxies are our Milky Way along with the Andromeda (also known as Messier 31) and Triangulum (also known as Messier 33) galaxies. This scientific visualization of a computer simulation depicts their joint evolution over the next several billion years and features the inev