Physicists plan to expand cosmic ray detector to seek universe's most energetic particles

Utah scientists announced a proposed expansion for their cosmic ray observatory, to speed up studies of on a "hotspot," a mysterious source of ultrahigh-energy cosmic rays.

Physicists plan a $6.4 million expansion of the $25 million Telescope Array observatory in Utah. Japan will contribute $4.6 million and University of Utah scientists will seek another $1.8 million to nearly quadruple the size of the existing 300-square-mile cosmic ray observatory in the desert west of Delta, Utah.

The expansion will allow the next step aimed at identifying what objects in space produce ultrahigh-energy cosmic rays, subatomic particles so energetic that just one would feel like a lead brick.

The planned expansion would make the Telescope Array almost as large and sensitive as the rival Pierre Auger cosmic ray observatory in Argentina. Together, they cover both the northern and southern skies.

While the observatory is focused largely on the mystery of ultrahigh-energy cosmic rays from far beyond the Milky Way galaxy, physicists also want to collect more information on lower-energy cosmic rays produced by exploding stars in Earth's galaxy.