This supercomputer simulation demonstrates one of the greatest powerful occasions in the universe: a pair of neutron stars striking, merging and creating a black hole. A neutron star is the dense core left behind when a star born with between eight and 30 times the sun’s mass detonates as a supernova. Neutron stars have about 1.5 times the mass of the sun compressed into a ball just 12 miles across. As the simulation initiates, we view an inequitably matched pair of neutron stars balancing 1.4 and 1.7 solar masses. They are parted by only about 11 miles, faintly less distance than their own diameters. Redder colors indicated regions of increasingly lower density.

Credit: NASA’s Goddard Space Flight Center

As the stars spiral to each other, penetrating currents begin to collapse them, maybe cracking their layers. Neutron stars hold unbelievable density, but their outsides are moderately thin, with densities about a million times greater than gold. Their centers crush matter to a much greater degree densities increase by 100 million times in their cores. To begin to visualize such mind-bending densities, iamgine that a cubic centimeter of neutron star material outweighs Mount Everest. Scientists consider neutron star fusions like this produce short gamma-ray bursts (GRBs). Short GRBs last less than two seconds however release as much energy as all the stars in our galaxy release over one year.