This magnificent image of spiral galaxy M81 combines data from the Spitzer Space Telescope, the Spitzer Space Telescope, and the Galaxy Evolution Explorer (GALEX) missions. The galaxy is tilted at an oblique angle on to our line of sight, giving us a top-down of its spiral structure. The galaxy is similar to our own Milky Way. M81 may be undergoing a surge of star formation along the spiral arms due to a close encounter it may have had with its nearby spiral galaxy NGC 3077 and a nearby starburst galaxy (M82) about 300 million years ago.
NASA, ESA, A. Zezas, JPL-Caltech, GALEX Team, J. Huchra et al., S. Willner