How many rings do you see in this cool space wallpaper of the galaxy Messier 94, also known as NGC 4736? While at first glance one might see a number of them, astronomers believe there is just one. Astronomers have recently discovered that the outer ring, seen here in the deep blue glow of starlight, might actually be more of an optical illusion. This image was captured in infrared light by NASA's Spitzer Space Telescope and released May 16, 2013.
(Image: © NASA/JPL-Caltech)