“From my own studies of the solar system I cannot entertain any serious possibility for intelligent life on the other planets, not even for Mars (the planet to which I have devoted considerable observation and study over the past thirty-five years). The logistics of visitations from planets revolving around the nearer stars is staggering. In consideration of the hundreds of millions of years in the geologic time scale when such visitations may possibly have occurred, the odds of a single visit in a given century or millennium are overwhelmingly against such an event.
“A much more likely source of explanation is some natural optical phenomenon in our own atmosphere. In my 1949 sighting the faintness of the object, together with the manner of fading in intensity as it traveled away from zenith towards the southeastern horizon, is quite suggestive of a reflection from an optical boundary or surface of slight contrast in refractive index, as in an inversion layer.
“I have never seen anything like it before or since, and I have spent a lot of time where the night sky could be seen well. This suggests that the phenomenon involves a comparatively rare set of conditions or circumstances to produce it, but nothing like the odds of an interstellar visitation.”
[[XII-1]] Air Force Files.
[[XII-1a]] Menzel, D. H. “The Truth About Flying Saucers.” Look magazine (June 17, 1952).
[[XII-2]] Johnson, C. L. Personal communication.
[[XII-3]] UFO Investigator, April-May 1961.
[[XII-4]] Coleman, W. T. Personal communication.
[[XII-5]] Nash, W. B. Personal communication.
[[XII-6]] Ruppelt, E. J. The Report on Unidentified Flying Objects. Garden City, N.Y.: Doubleday & Co., 1956.