MINOS far detector at the Soudan Underground Laboratory, Minnesota, USA. The Main Injector Neutrino Oscillation Search (MINOS) experiment studies neutrino beams using two detectors. The MINOS near detector, located at Fermilab near Chicago, records the composition of the neutrino beam as it leaves the Fermilab site. The MINOS far detector, located in Minnesota, half a mile underground, detects and analyses the neutrino beam. This allows scientists to directly study the oscillation of muon neutrinos into electron neutrinos or tau neutrinos under laboratory conditions. The 100-foot-long MINOS far detector consists of 486 massive octagonal planes, lined up like the slices of a loaf of bread. The detector has been fully operational, taking cosmic ray and