In ufology, a close encounter is an event in which a person witnesses an unidentified flying object. This terminology and the system of classification behind it were first suggested in astronomer and UFO researcher J. Allen Hynek's 1972 book The UFO Experience: A Scientific Inquiry.[1]

Hynek's scaleEdit

Hynek devised a sixfold classification for UFO sightings:[2][3] They are arranged according to increasing proximity.

Nocturnal Lights

Lights in the night sky.[4]

Daylight Discs

UFOs seen in the daytime, generally having discoidal or oval shapes.[5]


UFO reports that have radar confirmation. These seem to offer harder evidence that the objects are real, although radar propagation can often be unreliable.[6]

Close Encounters of the First Kind

Visual sightings of an unidentified flying object, seemingly less than 500 feet away, that show an appreciable angular extension and considerable detail.[7]

Close Encounters of the Second Kind

A 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.[7]

Close Encounters of the Third Kind

UFO encounters in which an animated creature is present. These include humanoids, robots, and humans who seem to be occupants or pilots of a UFO.[8]

Bloecher subtypesEdit

The UFO researcher Ted Bloecher proposed six subtypes for the close encounters of the third kind in Hynek's scale.[9]

A : An entity is observed only inside the UFO.
B : An entity is observed inside and outside the UFO.
C : An entity is observed near to a UFO, but not going in or out.
D : An entity is observed. No UFOs are seen by the observer, but UFO activity has been reported in the area at about the same time.
E : An entity is observed, but no UFOs are seen and no UFO activity has been reported in the area at that time.
F : No entity or UFOs are observed, but the subject experiences some kind of "intelligent communication".

* Subtypes D, E, and F may be unrelated to the UFO phenomenon. *

Extensions of Hynek's scaleEdit

Close Encounters of the Fourth Kind

A UFO event in which a human is abducted by a UFO or its occupants.[10] This type was not included in Hynek's original close encounters scale.[11]

Hynek's erstwhile associate Jacques Vallee argued in the Journal of Scientific Exploration that the "Fourth Kind" should refer to "cases when witnesses experienced a transformation of their sense of reality", so as to also include non-abduction cases where absurd, hallucinatory or dreamlike events are associated with UFO encounters.[12]

The film The Fourth Kind makes reference to this category.

Close Encounters of the Fifth Kind

A UFO event that involves direct communication between aliens and humans.[10] This type of close encounter was named by Steven M. Greer's CSETI group and is described as bilateral contact experiences through conscious, voluntary, and proactive human-initiated cooperative communication with extraterrestrial intelligence.[13] [14]

Close Encounters of the Sixth Kind

Death of a human or animal associated with a UFO sighting, although some might consider this as a more severe example of a second-kind encounter.[15][16]

Close Encounters of the Seventh Kind

The creation of a human/alien hybrid, either by sexual reproduction or by artificial scientific methods.[15]

See alsoEdit


  1. Hynek, Allen J. (1998) [First published 1972]. The UFO Experience: A Scientific Inquiry. Da Capo Press. ISBN 978-1-56924-782-2. 
  2. Steven J. Dick (28 December 1999). The Biological Universe: The Twentieth Century Extraterrestrial Life Debate and the Limits of Science. Cambridge University Press. pp. 309–. ISBN 978-0-521-66361-8. Retrieved 24 October 2011. 
  3. Donald Goldsmith; Tobias C. Owen (April 2001). The search for life in the universe. University Science Books. pp. 521–. ISBN 978-1-891389-16-0. Retrieved 24 October 2011. 
  4. J. Allen Hynek, The UFO Experience: A Scientific Enquiry, Ballantine Books, 1972, p. 41.
  5. J. Allen Hynek, The UFO Experience: A Scientific Enquiry, Ballantine Books, 1972, p. 59.
  6. J. Allen Hynek, The UFO Experience: A Scientific Enquiry, Ballantine Books, 1972, pp. 80-1.
  7. 7.0 7.1 J. Allen Hynek, The UFO Experience: A Scientific Enquiry, Ballantine Books, 1972, pp. 98-9.
  8. J. Allen Hynek, The UFO Experience: A Scientific Enquiry, Ballantine Books, 1972, p. 158.
  9. Hendry, Allan (August 1979). The UFO Handbook: A Guide to Investigating, Evaluating and Reporting UFO Sightings. Doubleday. ISBN 978-0-385-14348-6. 
  10. 10.0 10.1 What're close encounters of the first, second, third, fourth and fifth kind?. S.P.S. Jain. The Times of India. 22 March 2003. Retrieved 4 April 2014.
  11. The UFO Experience: A Scientific Enquiry. 1972. ISBN 978-1-56924-782-2. 
  12. Vallee, Jacques. "Physical Analysis in Ten Cases of Unexplained Aerial Objects with Material Samples Template:Webarchive." 1998. Journal of Scientific Exploration. Vol. 12, No. 3., pp. 359-375. URL accessed 23 August 2009
  13. Haines, Richard (1999). "CE-5 Close Encounters of the Fifth Kind.". Sourcebooks, Inc.. 
  14. McCarthy, Paul (December 1, 1992). "Close encounters of the fifth kind. (communicating with UFOs)". Omni. Archived from the original on 2007-05-12. Retrieved 2007-05-12. 
  15. 15.0 15.1 Judith Joyce, The Weiser Field Guide to the Paranormal: Abductions, Apparitions, ESP, Synchronicity, and More Unexplained Phenomena from Other Realms 2010, pp. 7.
  16. Stuart A. Kallen, Aliens (Monsters, and Mythical Creatures) 1995, pp. 24.


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