A planet-wide network of extraordinary instruments. Hover markers for details. Every glowing dot represents years of engineering and physics ambition.
Two of the world's most significant neutrino observatories in depth.
The IceCube Neutrino Observatory instruments a cubic kilometre of clear Antarctic ice with 5,160 digital optical modules (DOMs) deployed on 86 vertical strings between 1,450 and 2,450 metres depth. Each DOM houses a 25 cm photomultiplier tube and associated electronics sealed in a 33 cm glass pressure sphere.
Completed in 2010 after seven austral summer drilling seasons, IceCube transformed the South Pole into the world's largest particle detector. In 2013, the collaboration announced the first detection of high-energy astrophysical neutrinos — two events above 1 PeV nicknamed "Bert" and "Ernie." A broader astrophysical flux above 100 TeV has since been characterised.
Key results include the 2022 identification of NGC 1068 (M77) as a neutrino source at 4.2σ significance, the 2023 detection of galactic plane diffuse emission, and ongoing searches for dark matter, Lorentz violation, and exotic particles. The IceCube-Gen2 upgrade will expand the detector to 8 km³.
Super-Kamiokande is a 50,000-ton ultra-pure water Cherenkov detector in a cylindrical stainless-steel tank (41.4 m diameter × 39.3 m tall) located 1,000 metres underground in the Mozumi zinc mine. The inner detector wall is covered with 11,146 inward-facing 50 cm photomultiplier tubes giving 40% photocoverage.
In 1998, Super-K's analysis of atmospheric neutrinos showed a zenith-angle-dependent deficit of muon neutrinos — compelling evidence for oscillation, which requires mass. This overturned the massless-neutrino assumption of the Standard Model and won Takaaki Kajita the 2015 Nobel Prize.
Super-K receives a muon neutrino beam from the J-PARC accelerator 295 km away (the T2K experiment), measuring CP-violating phase δ_CP. The detector was upgraded with Gadolinium sulfate (SK-Gd phase) in 2020, enabling neutron tagging and dramatically improved supernova relic neutrino searches. Its successor, Hyper-Kamiokande, will be 5× larger.