The search for the truth continues...Ancient Aliens explores the controversial theory that extra-terrestrials have visited Earth for millions of years. From the age of the dinosaurs to ancient Egypt, from early cave drawings to continued mass sightings in the US, each episode in this hit History series gives historic depth to the questions, speculations, provocative controversies, first-hand accounts and grounded theories surrounding this age old debate. Did intelligent beings from outer space visit Earth thousands of years ago?