By Clara Moskowitz | LiveScience.com

A puzzling pattern in the cosmic rays bombarding Earth from space has been discovered by an experiment buried deep under the ice of Antarctica.

Cosmic rays are highly energetic particles streaming in from space that are thought to originate in the distant remnants of dead stars.

But it turns out these particles are not arriving uniformly from all directions. The new study detected an overabundance of cosmic rays coming from one part of the sky, and a lack of cosmic rays coming from another.

This odd pattern was detected by the IceCube Neutrino Observatory, an experiment still under construction that is actually intended to detect other exotic particles called neutrinos. In fact, scientists have gone out of their way to try to block out all signals from cosmic rays in order to search for the highly elusive neutrinos, which are much harder to find.

This "skymap," generated in 2009 from data collected by the IceCube Neutrino Observatory, shows the relative intensity of cosmic rays directed toward the Earth’s Southern Hemisphere. Researchers from the University of Wisconsin-Madison and elsewhere identified an unusual pattern of cosmic rays, with an excess (warmer colors) detected in one part of the sky and a deficit (cooler colors) in another. [Credit: IceCube collaboration, UW-Madison]