Extraterrestrial Hypothesis - Chronology

Chronology

Although ETH, as a unified and named hypothesis, is a comparatively new concept - one which owes a lot to the saucer sightings of the 1940s–1960s, it can trace its origins back to a number of earlier events such as the now discredited Martian canals and ancient Martian civilization promoted by astronomer Percival Lowell, popular culture including the writings of H. G. Wells and fellow science fiction pioneers such as Edgar Rice Burroughs, who likewise wrote of Martian civilizations, and even to the works of figures such as the Swedish philosopher, mystic and scientist Emanuel Swedenborg, who promoted a variety of unconventional views that linked other worlds to the afterlife.

Also in the early part of the 20th Century, Charles Fort collected accounts of anomalous physical phenomena from newspapers and scientific journals, including many reports of extraordinary aerial objects. These reports were first published in 1919 in The Book of the Damned. In this and two subsequent books, New Lands (1923) and Lo! (1931), Fort theorized that visitors from other worlds were observing Earth. Fort's reports of these early unknown aerial phenomena were frequently cited in American newspapers when the UFO phenomenon first attracted widespread media attention in June and July 1947.

The modern ETH - specifically the implicit linking of unidentified aircraft and lights in the sky to alien life - took root during the late 1940s and took its current form during the 1950s. It drew on pseudoscience as well as popular culture. However, unlike earlier speculation of extraterrestrial life, interest in the ETH was also bolstered by many unexplained sightings investigated by the U.S. government and governments of other countries, as well as private civilian groups, such as NICAP and APRO.