From the first time a person looked up at the sky and wondered "What''s out there?" humans have dreamed about exploring the cosmos.Over the years, there have been hundreds of reports of UFO (or unidentified flying object) sightings-which the U.S. government seemed to ignore. But a recently released Pentagon report tells a different story. For five years, a secret government agency was tracking and investigating these sightings. Now, in the pages of this book, the details of that report can be revealed! Share in the joy of exploration and discovery with UFOs.ABOUT THE SERIES: This book is part of A True Book series, Space Exploration, that includes the titles Human Missions to Outer Space, Mars Rovers, The International Space Station, and UFOs. The series features the latest NASA imagery and lively text to bring the wonder of space exploration directly to readers.