Powerful rays hitting Earth emitted from nearby galaxies

"We have taken a big step forward in solving the mystery of the nature and origin of the highest-energy cosmic rays, first revealed by the French physicist Pierre Auger in 1938," said the University of Chicago's James Cronin, a Nobel laureate and one of the nine authors of the report in the November 9 issue of Science.

The total 370 scientists on the team work at the facility in Argentina.

"We find the southern hemisphere sky as observed in ultra high-energy cosmic rays is non-uniform. This is a fundamental discovery," Cronin added.

"In the next few years our data will permit us to identify the exact sources of these cosmic rays, and how they accelerate these particles."