Super Stars

A neutron star is born out of a supernova explosion, which compresses the dying star's core—with a mass greater than the sun's—into a ball with a diameter the size of a small city. One step from becoming black holes, neutron stars are the densest objects in the universe. Just a teaspoon would weigh roughly a billions tons on Earth. In 2005, NASA scientists found the source of gamma-ray bursts that emit as much light as 100,000 trillion suns—and solved a 35-year mystery: When two neutron stars collided at speeds tens of thousands of miles per second, they emit gamma-ray fireworks.