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Aliens & UFOs

Do Aliens & UFOs exist? Has man been visited by other races from other worlds? Explore the fascinating evidence for and against the existence of extraterrestrials.

Hollow Earth Theory

Hollow earth theory was the brainchild of John Cleves Symmes, who sought to explore Earth's center. Read why some believe UFOs live inside the Earth. See more »

The Oz Factor

The Oz Factor is a sensation that UFO witnesses experience. Learn where the term "Oz Factor" came from, and what the experience is like. See more »

Space Animals

John Philip Bessor originally theorized that UFOs could be a form of space animal. Learn more about space animals and the UFO critter theory. See more »

Explaining UFOs

Both skeptics and believers spend time researching UFO reports and explaining UFOs as natural or supernatural events. Read more about explaining UFOs. See more »

UFOs & Government Secrecy

Does the government maintain secret contact with extraterrestrials? Learn about theories of UFOs and government secrecy in the CIA and the NSA. See more »

UFO Theory

UFO theories vary as widely in their credibility as in their imagination. Learn about theories of UFOs, aliens, spaceships, and the government. See more »

UFOs and the Government

Project Sign was the first major government UFO investigation project. Read how Project Sign began and the history of UFOs and the U.S. government. See more »

UFO History

Modern UFO history began with the 1947 UFO sighting by pilot Kenneth Arnold. Learn the history of UFOs from ancient times to the mid-20th century. See more »

How Area 51 Works

Area 51 is the most famous secret military installation in the world. Learn all about Area 51 and find out why Area 51 is such a heavily guarded secret. See more »

July 7, 1947: UFO Crashes in Roswell, N.M.

In July 1947, unusual debris was found in Roswell, N.M. The Army said they had a crashed disc, and later rescinded. Learn about the Roswell incident. See more »