The US Air Force commissioned the University of Colorado in 1966 to make a scientific study of UFOs. The project was headed by Dr. Edward Condon. In 1969 they published 'Scientific Study of Unidentified Flying Objects' which debunked the whole UFO phenomena. Later FOIA released documents have shown that CIA had involvement in the report and was responsible for the debunking reports. The Condon Report was just used as an excuse to close Project Blue Book without publishing. Incidentally, copies of the Condon Report are now very scarce.