Allen Hynek worked for US Air Force's project Blue Book as a consultant astronomer. In his own words, only "kooks and Crackpots" saw UFOs. But after a couple of years he started to notice that many of the reports weren't made up by kooks and crackpots, but by highly credible militaries and civilians. But after dismissing several credible witnesses at the Michigan sighting with the natural cause of swamp gas, he resigned.