The detection and study of neutrinos to learn about astronomical objects and the universe. Almost all current knowledge of the universe derives from the observation of photons. Radio waves, infrared radiation, visible light, ultraviolet waves, x-rays, and gamma rays are all electromagnetic waves composed of photons. Some further knowledge of the cosmos beyond the solar system is gained by observing cosmic rays, which are mostly protons and heavier atomic nuclei. But these positively charged particles do not point to their place of origin because of the magnetic fields of the Milky Way Galaxy, which bend their flight paths.