Becoming a planetary nebula is among the very last acts of a dying star. After a star similar in mass and composition to our sun nears the end of its several billion year life-span , it will balloon into a red-giant, before the outer layers of the star are flung into the interstellar medium, leaving behind a small, but dense core that emits large quantities of ionized gas..
This particular planetary nebula, IC 5148 lies about 3,000 light-years from Earth in the constellation of Grus (otherwise known as "The Crane"). IC 5148 - which is sometimes known as the Spare Tyre nebula, due to its ring-like appearance - has a current diameter that's around 3 light-years, yet it continues to expand at over 31 miles (50 kilometers) per SECOND -- effectively making it one of the fastest expanding planetary nebulae in the galaxy.
Download a high-resolution, larger image here.