Super-Kamiokande

The Super-Kamiokande observatory in Japan is filled with 50,000 tons of ultra-pure water. It utilizes this massive underground water tank, lined with 11,000 photomultiplier tubes, to detect the faint flashes of light (Cherenkov radiation) produced when elusive neutrinos interact with water molecules.

The observatory is located deep underground, roughly 1,000 meters (3,300 feet) below the surface, inside an abandoned zinc mine in the Kamioka area of Japan. Burying the detector under a mountain shields it from cosmic rays and other background radiation that could interfere with neutrino detection.

Yes, in 1998, the Super-Kamiokande collaboration announced definitive evidence that neutrinos oscillate between different flavors. This monumental discovery proved that neutrinos must possess mass, which earned the project's leader, Takaaki Kajita, a share of the 2015 Nobel Prize in Physics.

While Super-Kamiokande uses a massive tank of purified water inside a Japanese mine, IceCube uses a cubic kilometer of naturally frozen ice at the South Pole. Both rely on Cherenkov radiation to detect neutrinos, but their different mediums and geographic locations allow them to study different energy levels of cosmic events.