On Sept. 22, 2017, NSF's IceCube Neutrino Observatory alerted the international astronomy community that a high-energy neutrino had passed through the Earth. That notification set in motion follow-on observations from nearly two dozen observatories on Earth and in space, ultimately confirming the source of the neutrino, a first for science.
Shown in this animation, a neutrino that has traveled across space from a blazar, enters the ice of Antarctica. Just before reaching the IceCube detector, the neutrino collides with an atom's nucleus, resulting in a muon particle. The muon continues through the deep ice and emits blue light which is detected by the photosensors in IceCube.
Credit: Nicolle R. Fuller/NSF
