"The Andromeda galaxy is the closest large spiral galaxy to ours, and the brightest galaxy you can see. At 2.5 million light-years, it’s also the most distant thing visible to an unaided eye from Earth. Andromeda is thought to contain about a trillion stars, in comparison to the Milky Ways 250 billion. At one time, the Andromeda galaxy was called the Great Andromeda Nebula. Astronomers thought this patch of light was composed of glowing gases or was perhaps a solar system in the process of formation. "