If a galaxy is considered a stellar island, then a galaxy as big as the Andromeda galaxy must surely be a stellar continent. The Andromeda galaxy, designated M31 is the biggest galaxy in our local group. It’s about 220000 light years across, which means that it takes light to travel from the one end of the galaxy to the other whole 220000 years! In about 4.5 billion years from now, the Andromeda galaxy will drift towards us so much that the Milky Way will collide with it, forming the galaxy informally called Milkomeda.
Data: Jiří Žáček