Part of the In Search Of series, this documentary explores the possibility that aliens lived on the planet Earth thousands of years ago. Narrated by series host Leonard Nimoy, this video talks with both scientists who study extraterrestrial life and historians who study the prehistoric Earth. The program presents pictographs and other artistic renderings of the shape and size of these outer space creatures. Also, this video explores the possibility that if some aliens did not land on the surface of the Earth, they might have flown over the planet or into the Earth's atmosphere. ~ Cecilia Cygnar, Rovi