UFO Danger Zone

The book you are about to read is an exceptional account of adventure, a description of a true mystery. But it should also be read as something else: a wake-up call to scientists who are seriously interested in expanding the frontiers of our knowledge.
The person who goes into a bookstore in search of information about the UFO phenomenon is confronted with entire shelves proposing a bewildering series of volumes claiming to solve the enigma. Some offer arguments to support the idea that we are being visited by an advanced civilization from outer space; others take the opposite view, claiming that all the witnesses have been fooled by mirages and hallucinations, or by yet unrecognized aberrations of the mind. And every theory in between has its advocates and its detractors who often launch violent accusations against one another.
Opinions about UFOs are as varied and confusing as the phenomenon itself. Out of that confusion emerges this remarkable observation: These books offer a lot of speculation but few hard facts. They come from writers who analyze and compare accounts of sightings they have read in other books. They quote each other, often without proper attribution, without citing the source. They propagate old stories even when they are known to be false, and they speculate endlessly about possible causes and probable effects.