When neutron stars — the dense remnants of exploded massive stars — merge, we see a dazzling cosmic splash. But what happens in the moments before that happens? Astronomers used the Pleiades supercomputer at NASA Ames Research Center to run over 100 simulations of a system of two orbiting neutron stars. This was to explore how different magnetic field structures affected how all wavelengths of light leave the binary system. Most of the simulations showed the last 7.7 milliseconds before a merger

Neutron star collision