Can not be particles, called cosmic rays, and it seems with the energies of a million times higher than the largest particle accelerators on Earth can produce.
Astrophysicists believe that only two of the sources can make: supermassive black holes in active galaxies, or the so-called gamma ray bursts.
Study in the nature of it now has all but ruled out gamma-ray bursts is the cause.
Gamma-ray bursts (GRBs) are the brightest and the facts we know, although that is still debated origins. Can be released at times of more energy than our sun occur ever
