The Ring Nebula, catalogued as Messier 57, is one of the night sky's most celebrated planetary nebulae and a favorite target for backyard astronomers. Located approximately 2,300 light-years away in the constellation Lyra, this cosmic smoke ring represents the final gasp of a dying Sun-like star. What appears as a glowing oval or doughnut through most telescopes is actually a barrel-shaped shell of ionized gas expelled by a white dwarf star...