'Dark matter' search to go underground

CHICAGO, Aug. 11 (UPI) -- U.S. physicists say they'll take their search to find and identify the universe's "dark matter" to new depths -- into a Canadian mine almost a mile underground.

University of Chicago researchers will take bubble chambers, instruments that can detect cosmic particles, to SNOLab, part of the Sudbury Neutrino Observatory in Ontario, Canada, a university release said Wednesday.

They're hoping dark matter particles will leave tracks as they pass through the liquid in the chambers.

Dark matter accounts for almost 90 percent of all matter in the universe.

Invisible to telescopes, scientists assume its existence based on its gravitational influence on galaxies.

"There is a lot more mass than literally meets the eye," Juan Collar, associate physics professor at the University of Chicago, said. "When you look at the matter budget of the universe, we have a big void there that we can't explain."

Theorists suspect dark matter is made up of subatomic particles. Two likely candidates are weakly interacting massive particles and axions, which the researchers hope to capture in their bubble chambers.