Close encounters, in regards to UFO’s and extraterrestrial life, are broken down into four main categories which were primarily outlined by astronomer J. Allen Hynek. While there is always a level of disagreement as to whether UFO’s or ET’s exist, should they exist, contact of any sort would be categorized using Hynek’s scale. Since around 1972 when the Hynek scale first began gaining a degree of public recognition, it has been in use by both UFO enthusiasts and laymen alike.
Hynek actually only put forth three types of close encounters - from the first through the third kind. Over time however, a fourth kind was added along with many offshoots of each kind. For most UFO purists that strive to maintain a higher level of scientific objectivity, it is still only the original Hynek scale which is considered viable. Close encounters of the fourth kind are accepted by some, but so hard to prove that at this time they serve little purpose as there is no room to investigate such claims and endorse them as valid.
Under Hynek’s scale, a close encounter of the first kind is a sighting in which one or more unidentified flying objects have been spotted. This would include objects loosely described as flying saucers, objects which can not be attributed to known human technology that appear in the sky, or strange lights for which no rational explanation can be offered. Close encounters of the first kind are the most commonly reported events on the Hynek scale.
In most cases, there is an explanation for such encounters which does not tend toward the extraterrestrial. Hoaxes are not at all uncommon, especially in current times when technology capable of creating stunning simulations can be so easily obtained by so many. In many other cases, there are rational explanations that come out during investigation like military aircraft on certain types of training missions, weather balloons, satellites on the fritz, and at times, even lighted beacons on parachutists making night jumps. There are even geologic and normal atmospheric explanations for many others. In some cases however, there simply is no answer.
A close encounter of the second kind is a sighting of a UFO that also has some other phenomena associated to it. Phenomena that are generally accepted to upgrade a contact from the first to second kind include, frightened animals in the area, crop circles, land damage, electronic/mechanical interference, heat or radiation, catalepsy, and lost time which is a gap in a person’s memory at the time of the encounter.
The problem with validating encounters of the second kind is that they are highly questionable in regards to empiric investigation. Crop circles have been created by humans numerous times and the manner they are made has been exposed making them doubtful as evidence. Scared animals in the area could be attributed to many things - including the people in the area observing their perceived fear. Electronic and mechanical interference could be easier to show evidence of, but the genesis can often be rationally explained if localized. Catalepsy and lost time are entirely too easy to fake or make false claims of.
Close encounters of the third kind are those which have elements of the second kind, but include an observation of animate beings - ET’s. These are by far the rarest of the three kinds of encounters reported, the absolute hardest to prove, and as a matter of fact, Hynek himself did not actually want to include this type of contact on his scale. He did so however because so many people seemed to demand its inclusion. As such, he made it vague as to not endorse any specific image of what foreign life may or may not physically appear to be.
A close encounter of the fourth kind was not included on Hynek’s scale, but has gained support over the past quarter century or so. A close encounter of the fourth kind is perhaps the most controversial as it is based upon actual physical contact with the occupants of a UFO. This is generally termed as an alien abduction, although some have claimed that rather than being taken aboard a UFO, an alien life form has done any number of things to them or simply appeared to them, in the open, after exiting a UFO. The obvious problem with validating this has always been any physical proof, and the possibility of people reporting vivid dreams or hallucinations.