Andromeda Galaxy, or M31/NGC 224 is a spiral galaxy, with a diameter of 220,000 Light Years (LY). It's known as our galactic neighbor and a goddess. But don't mistake this Andromeda for a girl. It's a tempting sight to look at, and about 4.2 Billion years from now, Andromeda is now, Milkdromeda. In this term, Andromeda is the Universal Decimator or Catastrophic Overseer.