Most of us spend our lives chasing gold. For better or worse, this element determines many things over the course of our lives: where we can go to school, where we live, what kind of car we drive, who we marry, and even whether or not we eat. There are two rather simple reasons that we value gold so highly—it is beautiful, and it is rare.
And it’s not just rare on Earth; gold is also rare in the universe. Unlike other elements, such as carbon or iron, gold cannot be created within a star. Instead, it must be born in a more cataclysmic event, like an amazing celestial explosion.
And one such explosion occurred in September 2013. Researchers detected the Gamma Ray Burst (GRB) 3.9 billion light-years from Earth. GRB are among the brightest objects in the sky; however, no one has ever witnessed one of these fantastic events directly as the energy comes almost entirely in the form of gamma rays (hence the name). It is believe that GRBs happen when an extremely massive stars collapses onto black holes. Although most of the matter falls towards the black hole, some of its energy is focused into powerful jets that pummel out of the north and south poles of the star, making a gamma-ray burst. Another cause of GRBs is thought to be two ultra-dense neutron stars smashing into each other.
A team of researchers from the Harvard-Smithsonian Center for Astrophysicists calculated how much gold was created during the GRB, and their findings are mind-boggling. According to the study’s lead author, Edo Berger, "We estimate that the amount of gold produced and ejected during the merger of the two neutron stars may be as large as 10 moon masses - quite a lot of bling!" By combining the estimated gold produced by a single short GRB with the number of such explosions that have occurred over the age of the universe, all the gold in the cosmos might have come from gamma-ray bursts.
As Berger notes, observations of this GRB indicate that the event resulted from the collision of two neutron stars. These stars are the dead cores of larger stars that previously exploded as supernovae, and to paraphrase Carl Sagan, "we are all star stuff, and our jewelry is colliding-star stuff."