All the gold on earth is alien. Every atom of the precious metal probably came to us from violent collisions of dying stars, according to a team from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA.
The research team, led by astrophysicist Dr. Edo Berger, was studying the origins of short gamma ray bursts, two-tenths of a second-long blasts of radiation produced after the collision of two dying stars. Using the Magellan Telescopes at the Las Campanas Observatory in Chile, data from NASA's Swift satellite, and observations from the Hubble Space Telescope, the team observed the crash of two neutron stars, which occurred in a galaxy located about 3.9 billion light-years from earth.
Rare metals like gold can't be made in a normal star (hence their rarity on earth as well as the universe), but instead, they emanate from a cataclysm that produces short gamma ray bursts. The collision of two neutron stars fit the bill of such a necessary cataclysm. Their findings, published on June 17 in Astrophysical Journal Letters, also led researchers to estimated that all the gold on earth likely came from these stellar events. "We estimate that the amount of gold produced and ejected during the merger of the two neutron stars may be as large as 10 Moon masses -- quite a lot of bling!" said Berger.
Of course, the amount of gold estimated to exist on Earth is far less than that. As for the rest of the gold, could this new finding trigger a galactic gold rush?