A massive telescope buried in the Antarctic ice has detected 28 record-breaking, extremely high-energy neutrinos – elementary particles that likely originate far beyond our Solar System. (See Sections 12.7c and 13.2g)
The achievement, which comes nearly 25 years after the pioneering idea of detecting neutrinos in ice, provides the first solid evidence for astrophysical neutrinos from cosmic accelerators and has been hailed as the dawn of a new age of astronomy. The team of researchers that detected the neutrinos with the IceCube Neutrino Observatory in Antarctica published a paper describing the detections on November 22, 2013, in the journal Science.
The neutrinos had energies greater than 1,000,000,000,000,000 electron volts, or 1 peta-electron volt (PeV). Two of these neutrinos had energies many thousands of times higher than the highest-energy neutrino that any man-made particle accelerator has ever produced. (1 joule of energy = 6.2419 × 1018 eV.)
While not telling scientists what the cosmic accelerators are or where they’re located, the IceCube results do provide scientists with a compass that can help guide them to the answers. Unlike other cosmic particles, neutrinos are electrically neutral and nearly massless, so that they travel through space in a straight line from their point of origin, passing through virtually everything in their path without being deflected by interstellar masses and magnetic fields.
The IceCube observatory consists of over 5,000 basketball-sized light detectors called Digital Optical Modules (DOMs). These are suspended along 86 strings that are embedded in a cubic kilometer of clear ice starting 1.5 kilometers beneath the Antarctic surface. Out of the trillions of neutrinos that pass through the ice each day, a couple of hundred will collide with oxygen nuclei, yielding the blue light of Cherenkov radiation that IceCube’s DOMs detect.