Crab Nebula, composite image. Combined visible (blue) and infrared (red) image of the Crab Nebula, a supernova remnant 6000 light years distant in the constellation of Taurus. This is a shell of expanding gas and dust formed when a massive star imploded. Visible observations by the Hubble Space Telescope (HST) show emission from oxygen and sulphur ions. Far-infrared observations by the Herschel Space Observatory (HSO) show emissions from dust. Image data from the HST's Photoconductor Array Camera and Spectrometer (PACS) and the HSO's Wide Field and Planetary Camera 2 (WFPC2). Image published in 2013.