IceCube "skymap" showing varied cosmic ray intensity.
Cosmic rays ~ energy particles thought to originate in distant dead stars ~ are bombarding Earth in a pattern scientists find puzzling. They're are not arriving uniformly from all directions, but in an overabundance from one part of the sky and scarcity from another.
This odd pattern was detected by the IceCube Neutrino Observatory still under construction in Antarctica and intended to detect other exotic particles called neutrinos.
“IceCube was not built to look at cosmic rays ~ they are considered background,” University of Wisconsin-Madison researcher Rasha Abbasi tells LiveScience. “However, we have billions of events of background downward cosmic rays that ended up being very exciting.”
Previous studies have found a similar lopsidedness in the sky over the Northern Hemisphere, but this was the first time scientists saw that the pattern extended to the southern sky visible from Antarctica.
“At the beginning, we didn't know what to expect,” Abbasi adds. “To see this extending to the Southern Hemisphere sky is an additional piece of the puzzle around this enigmatic effect ~ whether it's due to the magnetic field surrounding us or to the effect of a nearby supernova remnant, we don't know.”