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Science and the UFO phenomenon:

"Statement on Unidentified Flying Objects"

This statement has been submitted by Dr. James E. McDonald, Senior Physicist, Institute of Atmospheric Physics, and professor, Department of Meteorology, The University of Arizona, Tucson, Arizona, to the House Committee on Science and Astronautics at July 29, 1968, Symposium on Unidentified Flying Objects, Rayburn Bldg., Washington, D.C.

I created a table of content below; which was not part of the original scientific publication. The 56 pages publication is some 250Kb and I broke it in several files for acceptable web access speed.

Please go to the Science section of this website for more scientific papers by James E. McDonald and other scientists, plus comments and information regarding scientists' work and position about the UFO phenomenon.

Table of content

Dr. James E. McDonald.

Why don't astronomers ever see UFOs?

I have had this question put to me by many persons, including a number of astronomers. Once I was speaking to a group from an important laboratory of astronomy when the director asked why astronomers never see them. In the room, among his staff, were two astronomers who had seen unconventional objects while doing observing but who had asked that the information they had given me about their sightings be kept confidential. I understand such restrictions, but some of them make things a bit difficult. This phenomenon of professional persons seeing unidentified objects and then being extremely loath to admit it is far more common than one might guess. After hearing of an evidently very significant sighting by a prominent physical scientist who was hiking in some western mountains when he spotted a metallic-looking disc, examined it with binoculars, and saw it shoot up into the air (according to my second-hand report from a professional colleague), I tried for months to secure a direct report of it from him; he was unwilling to discuss it openly with me. NICAP has had reports from prominent executives in large technical corporations who insisted that, just because of their positions, their names not be used publicly. Similar instances could be cited almost ad infinitum. The very types of witnesses whose testimony would carry greatest credence often prove to be the most reluctant to admit their sightings; they seem to feel they have the most to lose. Within a day of this writing, I spoke to a veteran airlines pilot about a sighting in which he was involved about a decade ago. After the official "explanation" was publicized, he decided he'd never report another one. I predict that social psychologists are going to have a field day, in a few years, studying the "pluralistic ignorance" that led so many persons to conceal so many sightings for so long.

Returning, however, to the question of why astronomers never see UFOs, a relevant quantitative consideration needs to be cited at once. According to a recent count, the membership of the American Astronomical Society is about 1800; by contrast, our country has about 350,000 law-enforcement officers. With almost 200 times as many police, sheriffs' deputies, state troopers, etc., as there are professional astronomers, it is no surprise that many more UFO reports come from the law-enforcement officers than from the astronomers. Furthermore, the notion that astronomers spend most of their time scanning the skies is quite incorrect; the average patrolman almost certainly does more random looking about than the average professional astronomer.

Despite these considerations, there are on record many sightings from astronomers, particularly the amateurs, who far outnumber the professionals. A few examples will be considered.

1. Case 20. Las Cruces, N.M., August 20, 1949:

A good account of the sighting by Dr. Clyde Tombaugh, discoverer of the planet Pluto, is given by Menzel (Ref. 25). From my own discussions with Dr. Tombaugh, I confirmed the main outlines of this incident. At about 10:00 p.m. on 8/20/49, he, his wife, and his mother-in-law were in the yard of his Las Cruces home, admiring what Tombaugh described as a sky of rare transparency, when Tombaugh, looking almost directly towards zenith, spotted an array of pale yellow lights moving rapidly across the sky towards the southeast. He called them to the attention of the two others, who saw them just before they disappeared halfway to the horizon. The entire array subtended an angle which Tombaugh put at about one degree, and it took only a few seconds to cross 50 or 60 degrees of sky. The array comprised six "windowlike" rectangles of light, formed into a symmetric pattern; they moved too fast for aircraft, too slowly for a meteor, and made no sound. Menzel quotes Tombaugh as saying, "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."


Dr. Menzel explains this phenomenon as resulting from reflection of lights from the ground, possibly "the lighted windows of a house" reflected by an inversion or haze layer aloft. The movement he explains as resulting from a ripple on the haze layer. Such an "explanation" is not merely difficult to understand; it is incredible. For an "inversion layer" to produce such a near-normal reflection of window lights would demand a discontinuity of refractive index so enormously large compared with anything known to occur in our atmosphere as to make it utterly out of the question. However, it has been just such casual ad hoc explanations as this by which Menzel has, in his writings, used meteorological optics to rationalize case after case with no attention to crucial quantitative details. It is a simple matter to show that even inversions of intensity many orders of magnitude larger than have ever been observed yield reflectivities (at the kind of near-normal incidence involved in Tombaugh's sighting) that are only a tiny fraction of one per cent (Ref. 36). In fact, I see no way of accounting for the Tombaugh observation in terms of known meteorological or astronomical phenomena.

2. Case 21. Ft. Sumner, New Mexico, July 10, 1947:

A midday sighting by a University of New Mexico meteoriticist, Dr. Lincoln La Paz, and members of his family was summarized by Life magazine years ago (Ref. 37) without identifying La Paz's name. Bloecher (Ref. 8) gives more details and notes that this is officially an Unidentified. At 4:47 p.m. MST on 7/10/47, four members of the La Paz family nearly simultaneously noted "a curious bright object almost motionless" low on the western horizon, near a cloudbank. The object was described as ellipsoidal, whitish, and having sharply-outlined edges. It wobbled a bit as it hovered stationary just above the horizon, then moved upwards, passed behind clouds and re-emerged farther north in a time interval which La Paz estimated to be so short as to call for speeds in excess of conventional aircraft speeds. It passed in front of dark clouds and seemed self-luminous by contrast. It finally disappeared amongst the clouds. La Paz estimated it to be perhaps 20 miles away, judging from the clouds involved; and he put its length at perhaps 100-200 ft.


This observation is attributed by Menzel (Ref. 24, p. 29) to "some sort of horizontal mirage, perhaps one of a very brilliant cloud shining like silver in the sunlight - a cloud that was itself invisible because of the darker clouds in the foreground." As nearly as I am able to understand that explanation, it seems to be based an the notion that mirage-refraction can neatly superimpose the image of some distant object (here his "brilliant cloud") upon some nearer object in the middle distance (here his "darker clouds"). That is a fallacious notion. If any optical distortions did here bring into view some distant bright cloud, it would not be possible to receive along immediately adjacent optical paths an image of the intermediate clouds. Furthermore, the extremely unstable lapse rates typical of the southwestern desert areas under afternoon conditions produce inferior mirages, not superior mirages of the looming type here invoked by Menzel. Rapid displacements, vertically and horizontally, are not typical of mirage phenomena. Hence Menzel's explanations cannot be accepted for this sighting.

3. Case 22. Harborside, Me., July 3, 1947:

An observation by an amateur astronomer, John F. Cole, reported to official investigative offices near the beginning of the period of general public awareness of the UFO problem, involves an erratically maneuvering cluster of about 10 objects, seen near 2:30 p.m. EDT on 7/3/47 on the eastern shore of Penobscot Bay. Hearing a roar overhead, Cole looked up to see the objects milling about like a moving swarm of bees as they traveled northwestward at a seemingly high speed, as nearly as he could judge size and distance. The objects were light-colored, and no wings could be discerned on most, although two appeared to have some sort of darker projections somewhat resembling wings. In 10-15 seconds they passed out of sight.


This is one of several dozen cases admitted to the Unidentified category in one of the earliest official reports on UFOs (Ref. 6). I have tried, unsuccessfully, to locate J. F. Cole. An account of the case is given by Bloecher (Ref. 8). It might be remarked that "swarming bee" UFO observations have cropped up repeatedly over the years, and from all over the world.

4. Case 23. Ogra, Latvia, July 26, 1965:

An astronomer whom I know recently toured a number of observatories in the USSR, and brought back the word that a majority of Russian astronomers have paid little attention to Russian UFO reports (details of which are quite similar to American UFO reports, my colleague established), a frequently-cited reason being that the American astronomer, Menzel, had given adequate optical explanations of all such sightings. I must agree with Dr. Felix Zigel who, writing on the UFO problem in Soviet Life (Ref. 38), remarked that Menzel's explanation in terms of atmospheric optics "does not hold water." It would, for example, be straining meteorological optics to try to account in such terms for a sighting by three Latvian astronomers whose report Zigel cites in his article. At 9:35 p.m. on 7/26/65, while studying noctilucent clouds, R. Vitolniek and two colleagues visually observed a starlike object drifting slowly westward. Under 8-power binocular magnification, the light exhibited finite angular diameter, so a telescope was used to examine it. In the telescope, it appeared as a composite of four smaller objects. There was a central sphere around which, "at a distance of two diameters, were three spheres resembling the one in the center." The outer spheres slowly rotated around the central sphere as the array gradually moved across the sky, diminishing in size as if leaving the Earth. After about 20 minutes' observation, the astronomers noted the outer spheres moving away from the central object, and by about 10:00 p.m., the entire group had moved so far away that they were no longer visible.


I have no first-hand information on this report, of course. The group of objects was seen at an angular elevation of about 60 degrees, far too high to invoke any mirage-effects or other familiar refractive anomalies. Furthermore, the composite nature of the array scarcely suggests an optical distortion of the telescope, a possibility also rendered improbable from the observed angular velocity and apparent recessional motion.

5. Case 24. Kislovodsk, Caucasus, August 8, 1967:

Zigel, who is affiliated with the Moscow Aviation Institute, reports in the same article (Ref. 38), a sighting at 8:40 p.m., 8/8/67, made by astronomer Anatoli Sazanov and colleagues working at the Mountain Astrophysical Station of the USSR Academy of Sciences, near Kislovodsk. Sazanov and ten other staff members watched an " asymmetric crescent, with its convex side turned in the direction of its movement" moving eastward across the northern sky at an angular elevation of about 20 degrees. Just ahead of it, and moving at the same angular speed was a point of light comparable to a star of the first magnitude. The crescent-like object was reddish-yellow, had an angular breadth of about two-thirds that of the moon, and left vapor-like trails aft of the ends of the crescent horns. As it receded, it diminished in size and thus "instantly disappeared".


If we may accept as reliable the principal features of the sighting, how might we account for it? The "faintly luminous ribbons" trailing from the horns suggest a high-flying jet, of course; but the asymmetry and the reddish-yellow coloration fail to fit that notion. Also, it was an object of rather large angular size, about 20 minutes of arc, so that an aircraft of wingspan, say, 150 feet would have been only about five miles away whence engine-noise would have been audible under the quiet conditions of a mountain observatory. More significant, if it had been an aircraft at a slant range of five miles, and at 20 degrees elevation, its altitude would have been only about 9000 ft above the observatory. For the latitude and date, the sun was about ten degrees below the western horizon, so direct sun-illumination on an aircraft at 9000 ft above observatory level would be out of the question. Hence the luminosity goes unexplained. Clearly, satellites and meteors can be ruled out. The astronomers' observation cannot be readily explained in any conventional terms. Zigel remarks that the object was also seen in the town of Kislovodsk, and that another reddish crescent was observed in the same area on the evening of July 17, 1967.

6. Case 25. Flagstaff, Ariz., May 20, 1950:

Near noon on 5/20/50, Dr. Seymour Hess observed an object from the grounds of the Lowell Observatory. Although Hess' principal field of interest has been meteorology, we may here consider him an astronomer-by-association, since he was at Lowell doing work on planetary atmospheres, on leave from Florida State University. Spotting an unusual, small object moving from SE to NW, he had time to send his son after binoculars, which he used in the later portions of his observation. He said it looked somewhat disc-shaped, or perhaps somewhat like a tipped parachute. It had no wings or visible means of propulsion. Dr. Hess indicated to me that he probably had it in sight a total of about three minutes, during which it passed directly between him and a cloud, before disappearing (into a cloud Hess feels, though this point was not certain). From meteorological data bearing on the cloud-base height, Hess deduced that the cloud bases lay 12,000 ft above terrain (vs. Weather Bureau visual estimate of 6000 ft above terrain). The zenith angle was about 45 degrees, so the slant range would have been 17,000 ft or 8,000 ft, depending on which cloud height is accepted. For its 3 minutes estimated angular diameter (dime at 50 ft, Hess estimated), the diameter would then come out of the order of 10 to 15 feet. His subjective impression was that it was possibly smaller than that.


The possibility that this might have been a balloon or some other freely drifting device comes to mind. However, Hess noted carefully that the clouds were drifting from SW to NE, i.e., at right angles to the object's motion. He estimated its speed to be in the neighborhood of 100 to 200 mph, yet no engine noises of any kind were audible. It appeared dark against the bright cloud background, but bright when it was seen against blue sky. No obvious explanation in conventional terms seems to fit this sighting.

7. Many other sightings by both professional and amateur astronomers could be listed. Vallee (Ref. 17) discusses in detail a November 8, 1957 observation by J. L. Chapuis of Toulouse Observatory in France of what appeared through a small telescope to be a yellowish, elliptical body, with distinct outlines, leaving a short trail behind it. It was seen by other observers in three separate locations, executed maneuvers entirely excluding meteoric origin, and was regarded as an unexplainable phenomenon by all of the witnesses. Hall (Ref. 10) lists nine examples of astronomer sightings of unidentified objects, several of which are quite striking. Ruppelt (Ref. 5) remarks that an astronomer working under contract to the official UFO investigatory program interviewed 45 American astronomers during the summer of 1952, of whom five (11 per cent) had seen what they regarded to be UFOs. Although the sample is small, that percentage is well above the population percentage who say they have seen UFOs, which suggests that perhaps astronomers may sight more UFOs than they report as such. Indeed, with the recent publication of Ref. 7, further interesting information on that 1952 poll is now at hand. The contract astronomer wrote at that time (Ref. 7, Rept. 8), "...certainly another contributing factor to their desire not to talk about these things is their overwhelming fear of publicity. One headline in the nation's papers to the effect that 'Astronomer Sees Flying Saucer' would be enough to brand the astronomer as questionable among his colleagues." Unfortunately, we scientists are by no means as open-minded and fearlessly independent as we are sometimes pictured. It is often quite difficult to persuade a scientist to let his confidential report of a UFO sighting become a fully open UFO report; and my own experience suggests that perhaps astronomers, as a group, are just a bit more sensitive on this score than other scientists. At any event, perhaps the above-cited cases will suggest that some astronomers have seen unidentified flying objects.

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