Credit: NASA/JPL-Caltech

                                           At approximately 2.5 million light-years away, the Andromeda Galaxy, or M31, is our Milky Way's largest galactic neighbor. The entire galaxy spans 260,000 light-years across -- a distance so large, it took 10 GALEX images stitched together to produce this view of the galaxy next door.

The wisps of blue making up the galaxy's spiral arms are neighborhoods that harbor hot, young, massive stars. Meanwhile, the central orange-white ball reveals a congregation of cooler, old stars that formed long ago.

Andromeda is so bright and close by that it is one of only three galaxies that can be spotted from Earth with the naked eye. This view is two-color composite, where blue represents far-ultraviolet light, and red is near-ultraviolet light.

Credit: NASA/JPL-Caltec