In the years following the launch of NASA's Hubble Space Telescope, astronomers have tallied over 1 trillion galaxies in the universe. But only one galaxy stands out as the most important nearby stellar island to our Milky Way -- the magnificent Andromeda galaxy (Messier 31).

This image, captured by NASA's Wide-field Infrared Survey Explorer (WISE), showcases the expansive Andromeda Galaxy, also referred to as Messier 31 or M31. This image of M31, our nearest major galactic neighbor, is the largest Hubble mosaic ever created, made up of 7,398 exposures from 411 separate telescope captures.