|The woo is out there|
|Aliens did it and ran away|
The belief that Nazi Germany built and operated "advanced propulsion craft" (i.e. flying saucers) that are responsible for (at least some) UFO sightings is a subset of the more general belief that (at least some) UFOs are vehicles of terrestrial origin. Different versions include either home-grown Nazi technology, or reverse-engineered alien technology. In scope, the claims vary from "mundane" top-secret craft limited to Earth's atmosphere to full-scale Nazi colonization of the Solar System. However, this allegedly sophisticated technology didn't exactly help them win the war.
The belief probably stems from the Nazis' forays in the occult (giving birth to the "Nazi mystique") and the reports of foo fighters by Allied warplane pilots during WWII. There is also the fact that Nazi Germany was the cradle of modern (space) rocket technology and that the people responsible for it later became very visibly involved in the US space effort. Robert Heinlein's Rocket Ship Galileo probably also bears some responsibility.
According to one version, the Nazis encountered an alien civilization and obtained some of their technology, resulting in the development of an anti-gravity engine called "Die Glocke" ("the bell"). Shortly before Germany's surrender, they somehow managed to sneak this device out to Antarctica, of all places, where they set up a new base. They're apparently still around, and when they're not busy bullying Jewish penguins, regularly patrol the globe, resulting in numerous UFO sightings.
Notable proponents include Vladimir Terziski and Jan Udo Holey (under the pen name Jan van Helsing). Richard Hoagland is a supporter of the idea.
 See also
- ↑ Robert Shaeffer: "Nazi Saucers and Antigravity", Skeptical Inquirer, vol. 33.1.