And these explosions make a lot of it — about 20 Earth-masses of gold in the June event, according to a back-of-the-envelope calculation by Daniel Kasen, a University of California at Berkeley astrophysicist. Kasen said that comes out to about 100 trillion oil tankers of gold.
"You need a lot of neutrons to throw at some seed nucleus to build it up to something heavy like gold or lead or platinum," Kasen said. "I'm partial to the name 'blingnova' to describe this kind of event, since what we are seeing is basically an ostentatious glimmering of riches."
If platinum is your thing, then rejoice: These collisions create seven times as much platinum as gold. Berger said the neutron-star collisions produce essentially everything up and down the periodic table.
There's still a lot that must be done with those gold atoms before they wind up on someone's front tooth. The gold is basically dust in the wind, atomized, until it winds up in a cloud of material that can coalesce, through the force of gravity, into a solar system of planets with a star at the center.
Then the gold atoms have to find one another and become concentrated. Over a billion years or more, the planet's geological processes will concentrate elements such as gold so that it will form veins and nuggets. Gold is chemically inert and doesn't want to bond with other elements.
"It's a process of distillation. That's what planets do," said Robert Hazen, a mineralogist at the Carnegie Institution of Washington. Gold is rare on Earth — about one part per billion in the Earth's crust, Hazen said.
Most of Earth's gold is trapped in the planet's core, he said. And, he added, there's a long-standing conjecture that at the very center of the Earth is a small core that's pure gold.
So, does Earth have a heart of gold? They haven't found a way to check on that — yet.