The Andromeda Galaxy, also known as Messier 31 or M31, is our closest major galactic neighbor. This giant spiral galaxy is a staggering 2.5 million light-years away, yet it can still be seen with the naked eye on a clear night, making it the farthest object visible without a telescope. With a diameter exceeding 200,000 light-years, Andromeda is larger than our Milky Way galaxy and is expected to collide with us in a few billion years, merging into a single behemoth galaxy. | The Brain Maze