Transcript: While scientists conduct, on a modest scale, the search for extraterrestrial intelligence, a significant number of people think we already know the answer. The majority of the American public believes that UFOs exist, that contact has already been made with aliens, that perhaps the government is hiding such information from us. Also, many people believe that there are biblical references to aliens or that alien visitations are encoded in many ancient human cultural artifacts like the pyramids or lines drawn on the plains of Mexico. The evidence for alien visitation is slim to none. Scientists raised a very high bar for deciding whether aliens have visited. As Carl Sagan said, extraordinary claims require extraordinary evidence. That evidence is not present in the case of UFOs and alien visitations. Virtually every scientist believes that there is no good evidence of alien visitations. It’s also clear there’s anthropocentric thinking involved. Ancient UFO sightings of course used to look like galleons in space in a time before there were spacecrafts. UFOs only started to look like rocket engines and spacecraft when we had that technology ourselves. If people want to believe, they will believe, but the scientific evidence does not favor any previous contact.