The $275m US-led IceCube telescope, located at the Amundsen–Scott research centre at the South Pole, comprises 86 cables, each up to 2.5 km long, suspended inside vertical holes in the ice. Attached to each cable are dozens of photomultiplier tubes. The photomultipliers record the Cerenkov radiation given off by the secondary particles created when incoming neutrinos collide with hydrogen or oxygen nuclei inside the ice.
The result was published in this week's issue of Science (Vol. 342, p. 920(2013)).