IceCube finds neutrinos from 47 million light-years away

Neutrinos are, in many ways, the most difficult species of known particle to detect at all. Produced wherever nuclear reactions or radioactive decays occur, you’d have to make a lead barrier that was approximately a light-year thick to have a 50/50 shot of stopping a neutrino in motion. Although there are many places neutrinos are made — in the Big Bang, in distant stars, in stellar cataclysms, etc. — the overwhelming majority of neutrinos we see come from just three sources: radioactive decays, the Sun, and from cosmic ray showers produced in Earth’s upper atmosphere. Still, the IceCube neutrino observatory, located deep under the ice at the South Pole, has revolutionized the science of neutrino astronomy. Since 2010, it’s sensitive to neutrino interactions within more than one cubic kilometer of glacial ice, <a href="https://medium.com/starts-with-a-bang/icecube-finds-neutrinos-from-47-million-light-years-away-2ad82017fcd8">Visit Now</a>