The important things to remember about UFOs are, first, that they are just alleged sightings that are unidentified—that is, they are not proof of anything— and, second, that eyewitnesses make identification difficult by so often being mistaken. As UFO investigator Allan Hendry (1979, 6) aptly noted, “We only get to study reports of UFOs—not the UFOs themselves.”
The term UFO is problematic. Often the phenomenon is neither “flying” nor an “object”; consider, for example, a bright disc that is really only the effect of a searchlight playing on a low cloud layer. Unidentified aerial phenomenon would be a more inclusive term (although itself not always accurate), but it seems we are stuck with UFO. Unfortunately, UFOs are mostly reported by untrained observers—those lacking necessary expertise in astronomy, atmospheric phenomena, aeronautics, physics, and perception, among other factors (McGaha 2009; Frazier et al. 1997). So, the widespread attitude that because they are unidentified they are therefore probably extraterrestrial craft is a logical fallacy called arguing from ignorance.
In fact—with careful, prompt investigation—most UFOs become IFOs, identified flying objects. To assist in this process, we have prepared the accompanying table (on pp. 35–36). It is necessarily oversimplified due to the number and complexity of factors involved. It cannot, of course, be expected to identify something that never existed (for example, a false claim) or that is—as so often is the case—seriously misperceived (such as a reflection on one’s window or windshield being perceived as a bright object at a distance). Nevertheless, the chart introduces several of the most common descriptions of UFOs, together LLwith some of their possible identifications. (We have drawn heavily on Allan Hendry’s The UFO Handbook [1979], supplementing it with other sources—e.g., Klass 1976, Sheaffer 1980, and Frazier et al. 1997—as well as our own experiences.)