According to NASA, a sugar-cube-sized portion of neutron star would weigh about a billion tonnes, or about the same as Mount Everest. A neutron star would typically be about 20 kilometres wide and weigh twice as much as the sun. The two neutron stars spiralled into each other until they collided and merged, as seen in this computer simulation. Astronomers had predicted that a neutron star merger would produce something that was 1,000 times as bright as a nova. He estimates neutron star mergers are responsible for half of the elements heavier than iron in the universe.

Source: CBC News October 17, 2017 19:30 UTC