All the Gold We've Mined Came From Space, New Study Says
Earth During Late Heavy Bombardment Artist's impression of the Earth during the period of the terminal bombardment. Julian Baum/Take 27 LtdThe core of the Earth has its own native-grown, inaccessible wealth, though When our planet was still forming, collisions with other planetesimals - and a Mars-sized object that sheared away the moon - turned the embryonic Earth into a roiling ball of molten rock. Iron and other heavy elements sank toward the core, and other iron-loving elements did, too. As a result, there's plenty of gold at our planet's center. So why, then, is there also gold in the hills? A new study supports the theory that it was all a gift from above. Meteorites seeded the Earth with a fresh, crust-level supply of noble metals half a billion years after the planet coalesced, British scientists say. And given how the Earth's crust has been mixed since then, the researchers speculate that...