Encounters with UFO's have been categorised into five groups. When a person sees a UFO within 150 metres, it's a close encounter of the first kind. When an encounter with a UFO in the sky or on the ground leaves evidence behind, it's of the second kind. When an encounter is visible with occupants within the UFO, it's of the third kind. The fourth kind involves the person being abducted. The fifth kind involves direct communication between aliens and humans.
