A close encounter (CE) is an event in which a person witnesses an unidentified flying object (UFO) at close range. Allen Hynek suggested in 1972 a scale of this kind of encounters that was extended by Jacques Vallee in 1990.
CE1. Close encounter of the first kind. Visual sightings of an unidentified flying object at such a distance that allows the observer to catch the object in considerable detail.
CE2. Close encounter of the second kind. An UFO event in which a physical effect is alleged; this can be interference in the functioning of a vehicle or electronic device, animals reacting, a physiological effect such as paralysis or heat and discomfort in the witness, or some physical trace like impressions in the ground, scorched or otherwise affected vegetation, or a chemical trace.
CE3. Close encounter of the third kind. UFO encounters in which an animated entity is present—these include humanoids, robots, or humans who seem to be occupants or pilots of a UFO.
CE4. A close encounter of the fourth kind is an UFO event in which a human is abducted by a UFO or its occupants. This type was not included in Hynek's original close encounters scale.
CE5. A close encounter of the fifth kind is where an alien abductee receives some manner of physical effect from their close encounter. In a CE5 event, individuals or groups use specific protocols to establish communication or interaction with extraterrestrial beings, such as meditation or the use of sounds or signals.
