Strands of gas and dust form the spectacular Crab Nebula, the remnant of a star that exploded almost a millennium ago as seen from Earth. The explosion acted as a chemical factory, creating many elements that were then expelled to space; they form different colored strands in this Hubble Space Telescope image. The nebula, also known as M1, spans about a dozen light-years in the constellation Taurus. [NASA/ESA/J. Hester/A. Loll (ASU)]