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Association for Aerial Anomaly Research and Cataloging

UFO and Paranormal Research from south-central Indiana

Always Watching the Skies


The Hynek UFO Classification System

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Dr. J. Allen Hynek

-- Lynn Taylor

Dr. J. Allen Hynek, late founder of CUFOS* (The Center for UFO Studies), developed the following classification system for use in analyzing UFO encounters. Hynek's system is used universally today.

Nocturnal Light: A visual sighting of a light on the sky at night. About 35 - 40 % of all reports are nocturnal lights.

Nocturnal Disc**: A visual sighting of a UFO in form of a structured light seen at night.

Daylight Disc: A visual sighting of a UFO with distinct shape seen at daytime.

Radar Cases: UFOs detected on radar.

Radar Visual Cases: UFOs detected on radar and visually at the same time. About 1 - 2% of all reports are radar visual cases.

Close Encounters of the First Kind: A UFO observed within 150 yards.

Close Encounters of the Second Kind: A UFO that leaves some kind of evidence like burn marks on the ground or fragments of unknown material.

Close Encounters of the Third Kind: A UFO with visible occupants.

Close Encounters of the Fourth Kind: Abductions.

Close Encounters of the Fifth Kind: Communication between a human and an alien.


** Added to the Hynek system later.

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Updated: February 05, 2006
AAARC and The Sentinel Files Copyright 1999