Circling high above the earth at 17,000 miles an hour, satellites uncover startling mysteries invisible to observers on the ground. With high magnification optics, infra-red scanning, and advanced ground-penetrating radar, they capture images that lead us on startling journeys into hidden worlds, revealing the secrets of the past and astonishing natural phenomena. Some of these images are breath-taking, but some are bizarre. One could be a vital clue to the location of the Garden of Eden, another might reveal the legendary golden city of El Dorado...