Democracy Dies in Darkness

In a cosmic first, scientists detect ‘ghost particles’ from a distant galaxy

July 12, 2018 at 11:00 a.m. EDT
At the South Pole, sensors at the IceCube observatory detected and identified the first source of high-energy neutrinos and cosmic rays. (Video: IceCube Collaboration/NSF)

When the sun was young and faint and the Earth was barely formed, a gigantic black hole in a distant, brilliant galaxy spat out a powerful jet of radiation. That jet contained neutrinos — subatomic particles so tiny and difficult to detect they are nicknamed “ghost particles.”

Four billion years later, at Earth’s South Pole, 5,160 sensors buried more than a mile beneath the ice detected a single ghostly neutrino as it interacted with an atom. Scientists then traced the particle back to the galaxy that created it.