1967 06 23 Bulletin of the Atomic Scientists - Vol 23 No 6 - Carl Sagan

Magazine Overview

Title: Bulletin of the Atomic Scientists
Issue: Volume 23, Issue 6
Date: June 1967
Publisher: Bulletin of the Atomic Scientists
Country: United States
Language: English
ISSN: 0096-3402 (Print), 1938-3282 (Online)

This issue features an article titled "Unidentified Flying Objects" by Carl Sagan, which was originally prepared for the Encyclopedia Americana and reprinted with permission.

Unidentified Flying Objects by Carl Sagan

Carl Sagan, from the Smithsonian Institution Astrophysical Laboratory, presents a report on unidentified flying objects (UFOs), examining the history of investigations, common explanations, and the prevailing hypotheses.

Investigations and Statistics

Sagan begins by recounting the origin of the term "flying saucers" from a sighting on June 24, 1947, near Mount Rainier, Washington. He notes the extensive publicity that followed and the subsequent similar sightings. The U.S. Air Force has been responsible for investigating UFO reports in the United States, with the number of investigated sightings varying significantly from year to year between 1947 and 1965. For instance, the period 1956-1960 saw 3,350 investigations, while 1961-1965 had 2,912.

Evaluation of Reports

Evaluating UFO reports is challenging due to their often sketchy nature, dissimilarities between reports of the same phenomenon, observer exaggeration, and deliberate hoaxes. Most reported UFOs are identified as belonging to categories such as unconventional aircraft, aircraft under unusual weather conditions, aircraft with unusual external light patterns, meteorological balloons, artificial satellites, flocks of birds, reflections from searchlights or headlights off clouds, reflections of sunlight from shiny surfaces, luminescent organisms, optical mirages, lenticular formations, ball lightning, sun dogs, meteors (including green fireballs), planets (especially Venus), bright stars, and the aurora borealis. Radar detection of UFOs has also occurred, with many explained as radar reflections from atmospheric temperature inversion layers or other sources of radar "angels."

Impact of Sputnik

Sagan highlights the remarkable fact that all but a few percent of reported UFOs have been identified as natural phenomena. He points out that the unidentified UFOs do not fall into uniform categories of motion or color, but rather exhibit the same range of variables as identified UFOs. The launch of Sputnik I in October 1957 is noted as a significant event; of the 1,178 UFO sightings in that year, 701 occurred between October and December, strongly implying that Sputnik and its publicity were responsible for many of these sightings.

The Robertson Panel

In July 1952, a set of visual and radar observations over Washington, D.C., caused substantial public concern. This led to the creation of a special panel in November of that year, established by the Office of Scientific Intelligence of the Central Intelligence Agency. Headed by H. P. Robertson of the California Institute of Technology, the panel concluded after a thorough investigation that all UFO reports to date were probably natural phenomena, wrongly interpreted.

Professional Astronomical Observations

Sagan emphasizes that the most reliable testimony comes from professional astronomers. He cites Jesse L. Greenstein, who noted that a large vehicle at high altitude would leave a distinct track on photographic plates, easily distinguishable from astronomical objects. However, it appears that such tracks or unambiguous visual observations of classical UFOs have never been made by professional astronomers. The Harvard Meteor Project (1954-1958), which used Super-Schmidt cameras to observe a large area of the sky, also failed to detect any unexplained objects, despite being sensitive enough to detect faint objects. These negative results from professional astronomers contribute to their general skepticism regarding flying saucer reports.

The O'Brien Panel and University of Colorado Study

A series of well-publicized sightings in the mid-1960s led to the appointment of another government investigating panel, this time under the Air Force Scientific Advisory Board, chaired by Brian O'Brien. This panel met in February 1966 and largely restated the conclusions of the Robertson panel, recommending that the Air Force make a more thorough effort to investigate selected UFO reports. In October 1966, the University of Colorado was selected by the Air Force Office of Scientific Research to manage a program and prepare a thorough analysis of the UFO problem, with the National Academy of Sciences agreeing to appoint a panel to review the Colorado report.

Hypotheses of Extraterrestrial Origin

Sagan addresses the hypothesis that a conspiracy exists to conceal the true nature of UFOs, suggesting that some might be space vehicles from intelligent extraterrestrial beings. He posits that Earth is likely not the only inhabited planet and that many stars have planetary systems. Given the rapid occurrence of life's origin on planets, it is plausible that a large number of planets in our galaxy are inhabited by technical civilizations. While interstellar space flight may be beyond current capabilities, there are no fundamental objections to its development by other civilizations. However, Sagan calculates that even with a million advanced civilizations launching spacecraft annually, our solar system would be visited only once every 100,000 years on average, making daily visits unlikely and anthropocentric.

Psychological Factors and "Contactees"

Sagan discusses "contact" tales, which describe landings of extraterrestrial vehicles and humanoid aliens. These tales are remarkably uniform and often involve aliens expressing concern about Earth's political situation and selecting a "chosen intermediary." He references psychologist Carl Jung, who noted the psychological significance of these persistent tales, even without objective evidence. Sagan suggests that the interest in UFOs may stem from unfulfilled religious needs, with flying saucers replacing deposed gods. The desire for unidentified flying objects to be of benign, intelligent, and extraterrestrial origin is strong, but Sagan insists that honesty requires evaluating observations with rigorous logic and convincing evidence.

Conclusion

Sagan concludes that at the present time, there is no evidence that unambiguously connects the various flying saucer sightings and contact tales with extraterrestrial intelligence. He stresses the importance of scientific rigor and evidence-based conclusions when examining the UFO phenomenon.

Recurring Themes and Editorial Stance

The Bulletin of the Atomic Scientists, through this article by Carl Sagan, adopts a stance of scientific skepticism and rigorous inquiry regarding the UFO phenomenon. The recurring themes include the importance of empirical evidence, the challenges of scientific investigation, the role of psychological factors in belief systems, and the need to distinguish between natural phenomena and unsubstantiated hypotheses. The editorial stance clearly favors evidence-based explanations and cautions against jumping to conclusions, particularly those involving extraterrestrial intelligence, without sufficient proof.