Cosmic rays zapping the Earth over the South Pole appear to be coming from particular locations, rather than being distributed uniformly across the sky. Cosmic ray “hotspots” have also been seen in the northern skies too, yet there is no source close enough to produce this strange pattern.
“We don’t know where they are coming from,” says Stefan Westerhoff of the University of Wisconsin, who used the IceCube neutrino observatory at the South Pole with a team of colleagues to create the most comprehensive map to date of the arrival direction of cosmic rays in the southern skies.
IceCube detects muons produced by neutrinos striking ice, but it also detects muons created by cosmic rays hitting Earth’s atmosphere. These cosmic ray muons can be used to figure out the direction of the original cosmic ray particle.
The mystery remains perplexing because the hotspots must be produced within about 0.03 light years of Earth… Read full article
Source and author: dailygalaxy