Nebulae come in all shapes, sizes and colors. The one pictured here falls on the smaller, and fainter, end of the spectrum. Called IC 4593, this planetary nebula can be found approximately 6,800 light-years from Earth in the Hercules constellation.
Like all planetary nebulae, IC 4593 is the result of a Sun-like star coming to the end of its life. Once it exhausted its hydrogen fuel supply, it resorted to burning off helium, before ballooning and shrinking in size drastically. Coinciding with the last step — when it focused its remaining mass into a dense core, about the same size as Earth, but much, much heavier — it threw off the remainder of its gaseous envelope, creating the colorful structure you see here.
NASA explains further:
See a larger image here.