Scientists have built a tank which contains 50,000 tons of ultra pure water and with about 13,000 photomultiplier tubes. The Super-Kamiokande detector is located one kilometre underground, in the depths of a Japanese mine.
The purpose is to detect neutrinos, a mysterious particle released by super-energetic events named supernovas which are rare and only happen three or four times in our galaxy every century.
The investigation of neutrino properties enable the understanding of how matter was created in the early universe.