Mysterious high-energy particles known as cosmic rays zip through space at a wide range of energies, some millions of times greater than those produced in the world’s most powerful atom smasher. Scientists have long thought cosmic rays from inside our galaxy come from supernova explosions, but a new study has fingered a second source: the supermassive black hole at the heart of the Milky Way. With this new result, the search for cosmic ray origins, which has frustrated scientists for more than 100 years, has taken an unexpected new twist._ Science AAAS![]()
