Crab Nebula

In 1054 AD Chinese and Arab astronomers noted a bright star in the sky. This was a supernova, the explosive death of a star. The cloud of gas left behind was first observed in 1731. It was eventually dubbed the Crab Nebula, because to some observers it was shaped like a crab. At the center lies the Crab Pulsar, a neutron star that is a strong source of radio waves and gamma rays. In addition to their astronomical significicance, these great clouds of gas and dust are often sources of interest due to their beauty, as seen in this mosaic by Arthur Gugick.