 | 130 million years ago, the ultra-dense cores of two dead stars collided. The first evidence of the cataclysmic collision were gravitational waves. They reached Earth on August 17th. As astronomers targeted their source, they turned up a trove of riches. It is explaining, among other things, the source of such precious metals as silver, gold and platinum. This is the first direct sighting of a collision between two neutron stars. The corpses of these stars are spectacularly dense. A single teaspoon of material would carry a mass that on Earth would weigh roughly one billion tons. |
 | Churning debris produced in the afterglow of the collision included newly created gold, silver and platinum. There was also a smattering of other heavy elements, including uranium. Until now, the birthplace of such elements had been theory. The extreme conditions produced in the collision forged heavier elements than the parent stars had hosted. |  |
 | The actual smashup now appears to have taken place 130 million light-years from Earth in the constellation Hydra. The afterglow revealed the birth of elements. As the collision spurted neutron-rich material into space, a variety of heavy elements formed through a chain of nuclear reactions known as the “r-process.” |
