UNIVERSITY PARK, Pa. — For the last 10 years, the unconventional IceCube Neutrino Observatory has been watching the cosmos, looking for signals of passing astrophysical neutrinos. These mysterious, tiny, extremely lightweight particles are created by some of the most energetic and distant phenomena in the cosmos. By identifying these neutrinos, the multi-institution IceCube collaboration — which includes several researchers at Penn State — can glimpse hidden parts of the universe.
The observatory itself is located at the South Pole, one of the coldest, driest, and most isolated places on Earth, and uses the Antarctic ice as an integral part of its detection system. During construction, crews drilled 86 holes nearly two-and-a-half kilometers deep and lowered a cable strung with 60 basketball-sized light detectors into each hole. The result was a hexagonal grid of sensors embedded in a cubic kilometer of ice about a mile below the surface of the Antarctic ice sheet. On Dec. 18, 2010, the 5,160th light sensor was deployed in the ice, completing the construction of the IceCube Neutrino Observatory.
“To detect neutrinos, we need a very large, kilometer-scale, detector made of optically clear material, and ice is an excellent option,” said Doug Cowen, professor of physics at Penn State and a charter member of the IceCube collaboration. “Because neutrinos travel through space without being deflected or absorbed, they have a unique ability to provide accurate information about where they came from in the distant universe, even billions of light-years away.”