According to Paranormal-Encylopedia.com: The term close encounter was coined by American astronomer and ufologist Josef Allen Hynek (1910 - 1986) in his 1972 book The UFO Experience: A Scientific Inquiry. Hynek proposed three types of close encounter: First Kind: Sighting of one or more UFOs at a distance of 500 feet or less. Second Kind: Sighting of a UFO with associated physical effects (e.g. heat, electrical interference, etc). Third Kind: Sighting of an animated being (presumably an alien but not specifically defined as such.)