Wolfgang Pauli proposed the existence of the neutrino in 1930, and it was named by Fermi in 1934.  The name, in Italian, can be loosely translated as "neutral baby."  Neutrinos are leptons, are chargeless, and have masses too small to measure by current methods.  They interact with other particles only via the weak interaction, by exchange of any one of the three weak bosons, W^± and Z⁰. Neutrinos from nuclear reactors were first detected directly back in 1956. In the nearly 70 years since then, neutrino telescopes have become a major tool of astrophysics. The detectors consist of a large volume of water or ice. Neutrinos are detected in these transparent media when they interact with nuclei by W exchange, converting into the equivalent charged lepton (muon or electron for muon neutrinos or electron neutrinos respectively), or when they elastically scatter off electrons (when the recoil electron can be detected). The created charged particles move at a speed much faster than the speed at which light propagates through the transparent medium, and create a wake of photons, like the wake of a boat which moves through water faster than surface water waves propagate. This so-called Cherenkov radiation is detected by huge systems of photon detectors. The best known of these neutrino telescopes is Ice Cube, which is located at the South Pole.

Closer to home, neutrinos and gravitational radiation are the only ways to examine just what precisely is going on in the very early stages of a supernova!

Apart from Icecube, the currently largest neutrino telescope is down in the Mediterranean Sea, and is known as KM3NeT.