Blog Post Image: NASA’s NuSTAR Untangles Mystery of How Stars Explode

Untangling the Remains of Cassiopeia A. This is the first map of radioactivity in a supernova remnant, the blown-out bits and pieces of a massive star that exploded. The blue color shows radioactive material mapped in high-energy X-rays using NuSTAR. Image credit: NASA/JPL-Caltech/CXC/SAO