This stunning picture of the supernova remnant Cassiopeia A is a composite of images taken by three of NASA's Great Observatories. Infrared data from the Spitzer Space Telescope are coloured red; optical data from the Hubble Space Telescope are yellow; and X-ray data from the Chandra X-ray Observatory are green and blue. Comparing the infrared and X-ray images could reveal how relatively cool dust grains coexist with superhot gas.