The mysterious Amaterasu particle may not be a proton at all. New research suggests that some of the most extreme cosmic rays ...

There may be an ultraheavy explanation for the mystery surrounding the origins of the highest-energy particles ever observed. Ultrahigh-energy cosmic rays are particles from space that strike Earth ...

For more than 60 years, physicists have chased one of the universe's most stubborn puzzles: where do the most energetic particles ever detected come from? A new study published May 7, 2026, in ...

Ultraheavy particle clue: Penn State-led research suggests some ultrahigh-energy cosmic rays are made of nuclei heavier than iron, altering theories on their origins. Record-breaking events: The 2021 ...

Cosmic rays seen at Earth show a wide range of particle energies, from 107 electron-volts (eV) to more than 1020 eV, the latter being about the same as the kinetic energy of a 450 gram football ...

"The origins and acceleration mechanisms of ultrahigh-energy cosmic rays have been among the biggest mysteries in the field for more than 60 years." When you purchase through links on our site, we may ...

High energy astrophysics studies the most violent processes in the Universe, from supernova explosions and pulsar winds to active galactic nuclei and cosmic‐ray acceleration. Galactic cosmic ...

Just 500 light years away, the Chamaeleon Complex, and in particular its dark cloud Chamaeleon I, is a hotbed of young, low-mass stars. When you purchase through links on our site, we may earn an ...

Artist’s impression of an ultra-high energy cosmic ray reaching Earth. New research suggests that some of the highest-energy cosmic rays may consist of atomic nuclei heavier than iron. The background ...