Enlarge ImageYounger than it looks. Astronomers compared radio (left, blue) and x-ray images (red) of this supernova remnant to determine that the explosion had occurred only 100 years before.Credit: NRAO (radio)/Chandra (x-ray) U.S. and British astronomers have located the youngest known remnant of an exploding star in the Milky Way. The discovery might help researchers understand why our galaxy seems to have so few supernovas and where the raw materials of planets and life came from. The Milky Way is a perfectly ordinary spiral galaxy, except for a shortage of supernova activity. These titanic explosions, which mark the deaths...