The Ring nebula (M57) is among the best known and most recognizable examples of a planetary nebula. Planetary nebulae receive their name from the fact that they look like distant planetary disks when observed through a telescope. They are produced when a red giant star (a star similar to our Sun, but in an older phase) blows up its gaseous outer layers. After this, it becomes a white star. M57 is located some 2,000 light years from Earth, in the direction of the constellation Lyra.