For years, people have reported seeing strange objects in the sky. Sometimes these take the form of lights or vague shapes; other times, the witnesses give detailed descriptions of what they believe to be alien spacecraft. In 2022, the United States Congress stated that reports of UFOs have been growing, but these flying objects often remain unidentified. What is the truth? Supplemented with informative graphic organizers and engaging fact boxes, the age-appropriate text delves into the history of UFO sightings and their probable explanations. A glossary of new terms also helps readers expand their scientific vocabulary.