Andromeda Galaxy.

The Andromeda Galaxy is a large spiral galaxy about 2.5 million light years from Earth. Named for its celestial location in the constellation of Andromeda, it is the closest major galaxy to the Milky Way—the home galaxy of our solar system. Andromeda is one of the most distant objects visible to the human eye without magnification, appearing as a fuzzy smudge of light about the diameter of a full moon. The galaxy, which is also known according to the classification M31, is larger than the Milky Way, and it was able to grow to its size by "consuming" several smaller neighboring galaxies. According to scientists, Andromeda is approaching the Milky Way. Several billion years in the future, the two galaxies will collide, merging to form a giant elliptical galaxy.