A Tale Of Two Neutron Stars: The Birth Of Gold
David Lin Wednesday March 28, 2018 12:57
(Kitco News) - How does one create as much gold that weighs about as much as the earth?
Simple: bring two neutron stars together.
Last summer, astronomers witnessed a powerful collision between two neutron stars, which saw the creation of precious metals like gold from the explosion. Months after reviewing the massive amounts of data gathered after the event, scientists now have a better understanding of how precious metals were created.
The amount of gold that was created would surprise you.
“We estimate that the collision created about as much gold as the mass of the Earth,” said Professor Andrew Levan of Warwick University, in an interview with the Financial Times. An estimated six billion trillion tonnes of gold could have been formed from one collision, the article said.
In comparison, since the beginning of civilization only about 187,000 tonnes of gold has been mined from the earth, according to data from the World Gold Council.
The collision helps to explain not just how gold was created but other heavier elements.
Scientists posit that the lightest elements formed by the Big Bang, hydrogen, helium and a little lithium, synthesized inside burning stars to form heavier elements up to iron.
“Since normal stars do not produce enough energy — or enough neutrons — to push the process beyond iron, astrophysicists need other explanations for the existence of gold and other heavy elements,” the article said.
The observation made last summer supplants a popular theory on the origin of gold held for several decades, which is that supernovae, violent explosions from the death of massive stars, form elements heavier than iron.
However, scientists now believe that the collision of neutron stars better explains the origins of precious metals.
“We felt pretty staggered that we had found something that seemed to match the theory so well,” said Prof Levan of Warwick. “We can make enough gold in neutron star collisions to do away with supernovae as a source.”
Neutron star collisions occur about once every 10,000 years in the Milky Way galaxy, according to the research.
The initial explosion sends debris, which contain gold, flying into space at about 300 million kph, about a third the speed of light. The debris accumulates in the cosmos in the form of meteorites. These meteorites eventually found their way to Earth’s surface.
“Earth suffered a sustained surface bombardment from metal-rich asteroids and meteorites up to 4bn years ago, after the core had formed, bringing most of the gold that we are mining today,” the Financial Times said.