MIT research published in Nature in April offers the first direct evidence that when a massive star explodes, some of its debris falls back toward its dense remaining core, called a neutron star. The resulting volatile disk of debris swirls around the neutron star like a 45 record with a marble at its center. (The colorized image to the left shows such a disk surrounding the neutron star Cassiopeia A, which is about 10,000 light-years away.)

Solar systems like our own usually coalesce from a cloud of gas, dust, and ice left over when a new star forms. From images taken by the NASA Infrared Spitzer Telescope, associate professor of physics Deepto Chakrabarty and his team deduced that the spinning cloud created when a massive star dies in a supernova explosion could also give rise to planets. Bathed in x-rays, any such planets would be virtually uninhabitable.