Ancient Aliens

What if life on Earth began in outer space? Are monuments like Stonehenge and Easter Island the last remains of an ancient alien visitation? This special investigates.

If ancient aliens visited Earth, what was their legacy, and did they leave behind clues that exist in plain sight such as sophisticated aircraft, complex electrical grids, and intricate construction machinery?

If ancient aliens visited Earth, who were they, and where did they come from? Possible historic evidence and beliefs are examined around the world.

If ancient aliens visited Earth, what was their mission, and is there evidence that points to when they will return? Ancient Sumerian tablets describe an alien race, known as the Anunnaki, who came to Earth to mine for gold.

Reports of encounters with strange beings and sightings of mysterious objects in the sky have occurred throughout history. A 13th century historical book, Otia Imperialia, includes an account of a creature descending from a flying craft.

There is evidence that suggests we experienced 20th century alien contact. In 1942, the Battle of Los Angeles involved the US military and Air Defense allegedly fighting a UFO.