IceCube neutrino detector uses Earth as filter to view deep‑space particles

The IceCube Neutrino Observatory is buried beneath the Amundsen‑Scott South Pole Station in Antarctica, with 5,160 glass‑sphere optical modules arranged on 86 vertical cables spanning a cubic kilometre of ice. The deepest sensors sit about 2,450 m below the surface.

IceCube detects high‑energy neutrinos that pass through the entire planet. A neutrino entering the Earth in the Northern Hemisphere can travel through thousands of kilometres of rock and ice before interacting in the detector, producing a brief flash of blue light that the instrument records. In this way the Earth itself serves as a natural filter and becomes part of the telescope.

Since its inception the observatory has confirmed the existence of astrophysical neutrinos from beyond the Solar System, linked some events to active galaxies, and in 2023 produced the first neutrino‑based map of the Milky Way.