1905-

Italian astronomer known for his research into cosmic rays and for discovery of the first confirmed x-ray source outside the solar system. In 1962, Rossi and his colleagues discovered an xray source in the constellation of Scorpio. Previously, x-rays had been detected from the Sun and from a number of terrestrial sources, but many thought they could not reach the Earth from outside the solar system. Rossi's discovery opened the door to x-ray astronomy, which has provided a great many discoveries of utmost importance about the universe.