Crab Nebula. This mosaic image, one of the largest ever taken by NASA's Hubble Space Telescope of the Crab Nebula, is a six-light-year-wide expanding remnant of a star's supernova explosion. Japanese and Chinese astronomers witnessed this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans (NASA Media Archives). Buy this as a superb wall poster, a canvas print or a framed print.