A
neutrino detector is a physics apparatus which is designed to study
neutrinos. Because neutrinos only
weakly interact with other particles of matter, neutrino detectors must be very large in order to detect a significant number of neutrinos. Neutrino detectors are often built underground, to isolate the detector from
cosmic rays and other background radiation. The field of
neutrino astronomy is still very much in its infancy – the only confirmed extraterrestrial sources so far are the
Sun and
supernova SN1987A. Neutrino observatories will "give astronomers fresh eyes with which to study the universe."