How is gold made? The mysterious cosmic origins of heavy elements

We have long struggled to figure out where heavy elements like gold come from. Now we have seen them being forged in neutron star collisions – and fresh clues suggest a role for the universe’s first stars

By Sapphire Lally

EVERYONE knows that ancient alchemists were obsessed with making gold. They never cracked it. Everyone knows that too. But here’s something not a lot of people know: thousands of years later, we still don’t fully understand where gold comes from. We can find it on Earth, of course. But where in the universe it was first made has long been a cosmic-scale mystery.

For most of the elements we are familiar with – carbon, oxygen, nitrogen – their origins are clear. These atoms were cooked up in the roiling hearts of stars through nuclear fusion. But bog-standard fusion is …