The Engraved Hourglass Nebula is a young planetary nebula in the southern constellation Musca about 8,000 light-years from Earth. It was discovered by Annie Jump Cannon and Margaret W. Mayall. It is conjectured that the nebula's hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud which is denser near its equator than its poles. The vivid colors given off by the nebula are the result of different 'shells' of elements being expelled from the dying star, in this case helium, nitrogen, oxygen and carbon.
