This new view of the historical supernova remnant Cassiopeia A, located 11,000 light-years away, was taken by NASA's NuSTAR. Blue indicates the highest energy X-ray light, where NuSTAR has made the first resolved image ever of this source. Red and green show the lower end of NuSTAR's energy range, which overlaps with NASA's high-resolution Chandra X-ray Observatory. // Credit: NASA/JPL-Caltech/DSS