Cosmic rays are primarily composed of protons, but also of helium, carbon, oxygen, and iron nuclei. Credit: © Chinese Academy of Science For more than 100 years, scientists have been trying to understand cosmic rays, incredibly powerful particles that travel across the universe at extreme energies. Despite decades of research, many questions about where they come from and how they are accelerated remain unanswered. Now, researchers working with the DAMPE (Dark Matter Particle Explorer) space