Andromeda Galaxy

The Andromeda Galaxy, also known as M31, is the closest spiral galaxy to our Milky Way, located about 2.537 million light-years away. It contains over a trillion stars and is roughly twice the size of our galaxy. Andromeda is on a collision course with the Milky Way, expected to merge in about 4.5 billion years. It can be seen from Earth with the naked eye as a faint smudge in the night sky. Studying Andromeda helps astronomers understand galaxy formation and evolution, contributing to our knowledge of the universe's structure and its history.