For years, astronomers have searched for the origins of ultra-high-energy cosmic rays, the most powerful particles in the universe. These energetic travelers move at nearly the speed of light ...

The most powerful cosmic rays raining down on Earth may come not from distant corners of the universe but from heavy dark ...

Cosmic rays may play a role in triggering lightning on Earth, a new study suggests. | Credit: Jan Drahokoupil / 500px / Getty Images Cosmic rays may offer an out-of-this-world answer to a long ...