Everyone's favorite precious metal has more explosive beginnings than previously thought. Scientists have announced new research showing gold may have ended up on Earth after a collision between two incredibly dense neutron stars, which are the collapsed cores of stars which exploded in a supernova. An event like this is only likely to happen once every 100,000 years. For years, researchers have believed that the period table's heaviest elements originated in supernova explosions. “We now have kind of a smoking gun,” said Edo Berger, the astronomer who led the research at the Harvard-Smithsonian Center for Astrophysics.