Final results from the University of Utah’s High-Resolution Fly’s Eye cosmic ray observatory show that the most energetic particles in the universe rarely reach Earth at full strength because they come from great distances, so most of them collide with radiation left over from the birth of the universe.

Breakthrough astrophysics research may have established the hitherto mysterious source of exceptionally high-energy cosmic ray emissions, according to recently published research that culminates a project developed by a scientist at the U.S. Department of Energy’s (DOE) Argonne National Laboratory.

Scientists of the Pierre Auger Collaboration, which includes New York University Physics Professor Glennys R. Farrar, have concluded that active galactic nuclei are the most likely candidate for the source of the highest-energy cosmic rays that hit Earth.