The subject of this breakthrough book is controversial, but its message is simple: the study of UFOs merits the serious attention of the intellectual establishment. Advocating credibility for this much-maligned field of research, historian David Jacobs and his coauthors highlight some of the key events, issues, themes, and theories surrounding this elusive, complex, and compelling subject.

Whether interplanetary tourists, interlopers from a parallel universe, or mere misfirings in the brain, UFOs and "aliens" permeate popular culture. They've made the covers of Time, Life, and the New...