Why "UAP" not "UFO"?

The term "UFO" was first coined in 1952 by a Captain. Edward J. Ruppelt, who led Project Blue Book, - the only official and public investigation into the UFO phenomenon by the United States Air Force (USAF). Ruppelt's term was quickly adopted by the USAF, which initially defined UFOs as 'those objects that remain unidentified after scrutiny by expert investigators'.

The term UFO is often used for any unexplained sighting irrespective of whether it has been investigated. Because of its immediate association for the general public with aliens or extraterrestrials and the media ridicule often connected with the subject, an increasing number of investigators now prefer to use other terms such as Unidentified Aerial Phenomena (or UAP). 

My own personal view is that it is unfortunate that the term UFO has now become so commonly associated with supposed flying craft containing 'little green men' (or 'space aliens' as my wife jokingly prefers to call them), especially when balloons, Chinese lanterns, lenticular clouds, meteorites, satellites, sun dogs - and many other earthly but ultimately explicable phenomena - could just as easily fall into the category of being 'UFOs' prior to being identified. So 'UFO' was quite useful as a scientific term until it (rather too quickly) fell into general misuse.

Consequently, those who generally say they 'believe in UFOs' are really saying they believe in the existence of craft of extraterrestrial or extra dimensional origin, which is far more dramatic than saying they believe in any flying object that has yet to be identified but which could be amongst the shortlist of explicable phenomena above.

To help sky watchers in identifying some of the less-obvious phenomena I've listed above I will include brief explanations of these (and others) in another post with corresponding images.