IceCube detection of high-energy particle proves 60-year-old physics theory The electron antineutrino that created the Glashow resonance event traveled quite a distance before reaching IceCube. This graphic shows its journey; the blue dotted line is the antineutrino’s path. IceCube Collaboration On Dec. 8, 2016, a high-energy particle hurtled to Earth from outer space at close to the speed of light. The particle, an electron antineutrino, smashed into an electron deep inside the ice sheet at the South Pole. This collision produced a particle that quickly decayed into a shower of secondary particles, triggering the sensors of the IceCube Neutrino Observatory, a massive telescope buried in the Antarctic glacier.