The great age of exploration in the 1500s witnessed the creation of its own folklore: sea serpents, unicorns and unipeds, the Fountain of Youth and the Seven Cities of Cibola. Not surprisingly, the young Space Age has also witnessed a similar body of myth and legend, based on rumors, travellers' tales, misinterpretations, wild imaginations, and self-serving fabrications.

This lecture elucidates the most popular of these stories and to trace them to their sources, not merely to refute them but to understand the processes which created them and helped them spread. Their popular appeal is analyzed. Related, authentic mysteries are discussed, along with guidelines for telling the difference. The tone is humorous and sympathetic, not negative.

In a culture of conspiracies, why not imagine a conspiracy to either "fake" the moon flights, or to conceal a vast array of moon bases -- and new books, articles, WWW pages, and lectures have appeared on this theme. Meanwhile, many UFO stories around the world are based on honest public misperception of space and rocket activity. The most interesting case occurred in the Soviet Ukraine in the late 1960's, when secret space weapons tests caused fireballs to appear frequently in the evening sky. The public reported these as "crescent-UFOs" and that's the way they are recorded in the UFO literature. An official team from Moscow's Academy of Sciences even published a formal study verifying that the phenomenon was unexplainable in earthly terms. But it was all a coverup of an illegal weapon which the USSR had signed a treaty promising not to deploy. Similar UFO cases from Russia, China, France, Argentina, and the US can be traced back to unusual space activities.

It is widely believed that "astronauts have seen UFOs, too", in space and on the Moon, and dozens of stories are in circulation. The grandest involve Apollo-11 and allegations of secret photographs and transcripts. It is amusing and instructive to trace these legends as they migrate from country to country, book to book, growing and 'improving' along the way.

Other tales include: the "face on Mars"; the "bridge on the Moon", the vanished Linne crater, and similar lunar illusions; the "Somebody Else is on the Moon" syndrome; the "Tunguska Blast" of 1908 and the idea it was an alien nuclear-powered spaceship; "the Great Galactic Ghoul", which came back to life to grab Fobos-1 and NASA's "Mars Observer"; strange television signals from space; the "missing day in time", in which a NASA computer allegedly verified the Book of Joshua; ex-post-facto rewriting of Velikovskian planetary predictions; and many more myths and legends of the Space Age.

Such worldwide mythology of space has helped to humanize this new alien frontier, which is culturally beneficial. But it also raises questions about the level of information on which the media and public is basing technical and political judgments. Other fallacies of space flight are mentioned, and new approaches to public information policies are suggested. Perhaps because NASA has made spaceflight boring, it's not surprising people seek excitement in alternate perceptions of the newest human frontier, outer space.