Mining for Gold

If you want to scoop up a lot of gold, just hang around a close pair of neutron stars. If the stars spiral together, they can produce amazing amounts of gold, silver, and other heavy elements. In fact, a merger that was seen in late 2021 produced enough to make a thousand planets as massive as Earth.

A neutron star is the tiny, ultra-dense corpse of a once-mighty star. At the end of its life, the core of such a massive star collapses. The star’s outer layers then explode as a supernova.

In December of 2021, astronomers saw the merger of two neutron stars. The stars were in a galaxy more than a billion light-years away. That was close enough to study the event in detail.

It began with a gamma-ray burst — an extremely powerful outburst of energy. It shined far brighter than the combined light of many galaxies of stars. The outburst lasted for less than a minute. That length suggested the outburst was powered by the collapse of a massive star.

But detailed analysis proved otherwise. The event was the result of the merger of two neutron stars. Much of their material splattered out into space. Temperatures were so extreme that atoms slammed together to make heavier elements — including gold and silver. The remnants of the two stars then merged to make a black hole. But many of the heavy elements escaped. Some of them may since have been incorporated into new planets — perhaps to adorn the people of future civilizations.

Script by Damond Benningfield