This introduction summarizes key points about the UFO phenomenon and the debate around it. It notes that while many sightings have conventional explanations, a minority of cases like the 1964 Socorro, New Mexico sighting described in detail remain unexplained. It also discusses reports of "humanoids" or small figures seen near UFOs. The introduction argues more scientific study is needed of this phenomenon, which could potentially represent an unprecedented event - contact with extraterrestrial intelligence.