Where did Gold come from on Earth? Black Hole connection found!

Have you ever wondered how heavy metals such as Gold reached Earth or how they got formed? It is now being that these metals were formed in some terribly harsh conditions such as inside stars, stellar explosions, and neutron star collisions, which were later deposited on our planet over the millions of years of asteroids and meteor bombardments that went on to form the Earth.

A recent study by the German researchers from the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt showed the formation of heavy metals in Black Holes, using computer simulations. Even the detection of gravitational waves and electromagnetic radiation from a neutron star merger in 2017 revealed that these cosmic events can produce and release a large number of heavy elements.

Though, the question still remains the same - why and when is the material ejected from Black Holes? Also, is there is a possibility of other scenarios in which heavy metals can be produced? Dr Oliver Just from GSI's research division Theory mentioned that, “In our study, we systematically investigated for the first time the conversion rates of neutrons and protons for a large number of disk configurations by means of elaborate computer simulations, and we found that the disks are very rich in neutrons as long as certain conditions are met.”

Science behind the gold formation and other metals

For the formation of heavy metal elements such as Gold, Uranium, a high number of neutrons is what is needed as it enables the rapid neutron-capture process or in short known as ‘r-process’. As the system is formed both after the merger of two massive neutron stars and during collapsar - the collapse and subsequent explosion of a rotating star, Black holes seems a promising candidate with its accretion disk of dense and hot matter.

Dr Just explained that more the mass of the disk, means more often neutrons are formed from protons through the capture of electrons. If the disk's mass is too high, however, the inverse reaction becomes more important, and more neutrinos are captured by neutrons before they leave the disk. After this process, the neutrons are transformed back to protons.

These results of the study suggest and provide strong evidence that merging of neutron stars producing the accretion disks with these exact masses could be the point of origin of gold and other metals.