Since the middle of the last century, many people around the world have reported sightings of unidentified flying objects (UFOs) and speculated that they were alien spacecraft. Some witnesses have reported seeing nonhumans emerge from otherworldly craft and even having interactions with these intelligent beings. While most scientists believe these tales to be hallucinations or hoaxes, the sheer number of reports of alien encounters, the similarities between them, and the emotional impact they have had on witnesses make the phenomenon difficult to dismiss. Fans of the paranormal will enjoy delving into juicy, eyewitness tales from the United States and around the world. Assessing the evidence, readers can decide for themselves whether someone else is truly out there.