Some 130 million years ago, in another galaxy, two neutron stars spiraled closer and closer together until they smashed into each other in spectacular fashion. The violent collision produced gravitational waves, cosmic ripples powerful enough to stretch and squeeze the fabric of the universe. There was a brief flash of light a million trillion times as bright as the sun, and then a hot cloud of radioactive debris. The afterglow hung for several days, shifting from bright blue to dull red as the ejected material cooled in the emptiness of space.
Astronomers detected the aftermath of the merger on Earth on August 17. For the first time, they could see the source of universe-warping forces Albert Einstein predicted a century ago. Unlike with black-hole collisions, they had visible proof, and it looked like a bright jewel in the night sky.
But the merger of two neutron stars is more than fireworks. It’s a factory.
Using infrared telescopes, astronomers studied the spectra—the chemical composition of cosmic objects—of the collision and found that the plume ejected by the merger contained a host of newly formed heavy chemical elements, including gold, silver, platinum, and others. Scientists estimate the amount of cosmic bling totals about 10,000 Earth-masses of heavy elements.
The Plume of Gold Ejected by a Cosmic Collision
Between A.D. 307 and 324, the worth of one pound of gold in Rome rose from 100,000 denarii (a Roman coin) to 300,000 denarii. By the middle of the fourth century, a pound of gold was worth 2,120,000,000 denarii—an early example of runaway inflation, which was partly responsible for the collapse of the Roman Empire.
How Gold is made and how it got to our planet
