Far-off galaxies are firing rare high-energy cosmic rays at us

Noted: Other telescopes have also been looking at the extreme universe of high-energy particles by searching for highly energetic neutrinos and gamma rays. “The energy density in the extreme universe observed in cosmic rays, in neutrinos and gamma rays turns out to be the same,” says Francis Halzen at the University of Wisconsin-Madison and the principal investigator of the IceCube Neutrino Observatory. “This may point at common sources and not be an accident.”