A Science Experiment in South Pole Ice Searches For Clues About Dark Matter
A Photo Sensor Is Lowered Into Antarctic Ice Courtesy Mark Krasberg/NSF Every December since 2004, engineers have flown to the South Pole to drill 8,000-foot-deep holes in the ice. The team lowers cables, each strung with 60 disco-ball-size light sensors, into the holes and let them freeze over. So far they have completed 79 such holes, set in a grid half a mile on each side, and plan to drill the final seven this month. The result will be the IceCube Neutrino Observatory, a cube of ice packed with 5,320 sensors looking for cosmic particles. Neutrinos are subatomic particles created by radioactive decay or nuclear reactions. Like other types of extrasolar radiation, they emerge from energetic cosmic events and constantly bombard Earth. Neutrinos are unique among cosmic particles, however, in that they carry no electric charge. The magnetic fields of stars and planets bend the paths of charged particles, making it...