Scientists find evidence of supernova explosions relatively close to Earth

Scientists at the Australian National University (ANU) have discovered evidence for supernova explosions in the interstellar space around our Solar System, from analysing deep-sea sediments. Supernovas (or supernovae) are the super-powerful explosions which mark the death of massive stars. All stars are powered by nuclear fusion reactions, as a consequence of which stars convert hydrogen into ever-heavier elements, which they are able to do because of their density and gravity.  Massive stars are so dense and have so much gravity that they end up producing iron in their cores. But they cannot burn iron, so the metal accumulates in their cores, killing the star from the inside, finally resulting in a supernova, which blasts all the elements created by that star, including the iron, across space. What is left often, but not always, collapses into a black hole.