Plusieurs Objets Volants Non Identifiés (OVNIs) furent observés et photographiés vers 11 h 10 (MST) le 2 juillet 1952 par Delbert C. Newhouse en un point de la State Highway 30, à plusieurs miles au nord de Tremonton (Utah) (latitude 41° 50", longitude 112° 10'). M. Newhouse, un chief Warrant Officer de la Marine U.S., n1à l'époque il avait déjà enregistré quelques 2200 h en tant que chef photographe avec la Navy, était en transit depuis Washington (D.C.) à Portland (Oregon). Une carte de la région est incluse en figure 1.
Lui, sa femme et leurs 2 enfants faisaient le voyage en voiture. Peu après être passé à travers la ville de
Tremonton, sa femme remarqua un groupe d'étranges objets brillants en l'air au loin vers l'horizon est. Elle attira
sur eux l'attention de son mari et lui intima d'arrêter la voiture. Lorsqu'il sortit, il observa les objets (12 à 14
d'entre eux) qui étaient directement au-dessus et milling about. Il les décrivit comme des objets de la couleur du
métal d'un pistolet ayant la forme de 2 soucoupes, l'un inversée au sommet de l'autre
. Il estima qu'ils
sous-tendaient à peu près le même angle que celui d'un B-29 à 10 000 pieds
(environ 1/2 ° -- i.e., à peu près
le diamètre angulaire de la Lune). (Next, he ran to the trunk
of his car, took out his Bell and Howell Automaster 16mm movie camera equipped with a 3" telephoto lens, loaded it,
focused it at infinity and began shooting. There was no reference point above the horizon so he was unable to estimate
absolute size, speed or distance. He reports that one of the objects reversed its course and proceeded away from the
rest of the group; he held the camera still and allowed this single object to pass across the field of view of the
camera, picking it up later in its course. He repeated this for three passes.
Pendant le tournage, Newhouse changea le iris stop of the camera de f/8 à f/16. La densité du film can be seen to change markedly at a point about 30% through the sequence. The camera was operated at 16 fps.
Le film couleur (Daylight Kodachrome) après
développement fut soumis à ses supérieurs. La Marine fit suivre le film à l'USAF-ATIC où le film fut étudié pendant plusieurs mois. Selon Al Chop
(alors avec l'ATlC et actuellement avec la DAC) le personnel de l'Air Force était convaincu que les objets n'étaient pas des avions ; d'un autre côté l'hypothèse que la caméra ait pu n'avoir pas fait le point et les objets être des
mouettes en vol plané ne put être ni confirmée ni rejetée. Les remarques de M. Chop sont
essentiellement etayées par le capitaine Edward Ruppelt, référence (1) alors directeur du projet "Blue Book" pour l'ATIC.
A 35mm reprint of the Newhouse "Utah" film was submitted to Douglas Aircraft Company for examination. Visual study of the reprints on the Recordak and astronomical plate measuring engine revealed the following: The film comprises about 1200 frames; on most of the frames there appear many round white dots, some elliptical. The dots often seem clustered in constellations, or formations which are recognizable for as long as seventeen seconds. A relative motion plot (obtained from an overlay vellum trace on the Recordak) of two typical formations are presented. The objects seem to cluster in groups of two's and three's. On some frames they flare up and then disappear from view in 0,25 s or less and sometimes they appear as a randomly scattered "twinkling" of dots. The dot images themselves show no structure; they are white and have no color fringes. Examination under a microscope shows the camera to be well focused as the edges of the images are sharp and clear on many of the properly exposed frames (of the original print). Angular diameters range from about 0.001,6 to 0.000,4 radians. Their pattern of motion is essentially a curvilinear milling about. Sometimes the objects appear to circle about each other. There are no other objects in the field of view which might give a clue as to the absolute motion of the cluster.
In the overlay trace, the frame of reference is determined by a certain object whose relative motion during a sequence of frames remains rather constant. This object is used as a reference point and the lower edge of the frame as abscissa. Assuming the camera to have been kept reasonably uncanted, the abscissa would be horizontal and the ordinate vertical. In the overlay trace, the particular frame itself is used as the reference. Assuming the camera was held steady (there is an unconscious tendency to pan with a moving object) the coordinate system is quasi-fixed. It is realized that both of these coordinate systems are in actuality moving, possibly possessing both velocity and acceleration.
No altitude or azimuth determination can be made because of lack of background. The only measurable quantities of interest are therefore the relative angular distances between the objects and their time derivatives. Graphs of two typical time variations of relative angular separation and velocity are included (in Baker and Makemson (1967)). The relative angular velocity is seen to vary from zero to 0.006,5 radians per second. The relative angular acceleration had a maximum value of 0.003,6 radians per second squared. Supposing the camera was kept stationary the average angular velocities for the object moving across the field are 0.039 and 0.031 radians per second. The angular velocities in these sequences sometimes vary erratically from 0.07 to 0.01 radians per second. This variation may be attributed in part to camera "jiggling" and in part to the object's motion. The decrease in average angular velocity could be due to the object's having regressed between filmings just as was reported by Newhouse. Also the average image diameter decreases about 30% over the entire film, indicating a possible over-all regression of the objects.
The following tabulation indicates the hypothetical transverse component of relative velocities and accelerations at various distances. It is noted that the transverse velocity may be only a fraction of the total velocity so that the numbers actually indicate minimum values.
| Si la distance de l'objet était - | Si la vitesse transverse était de - | Si l'accéleration transverse était de - | Vitesse de l'objet seul était de - |
|---|---|---|---|
| 100 pieds | 0,65 pied/s ou 0,44 miles/h | 0,36 pied/s2 ou 0,011g | 3,8 pieds/s ou 2,7 miles/h |
| 1000 pieds | 6,5 pieds/s ou 4,4 miles/h | 3,6 pieds/s2 ou 0,11 g | 39 pieds/s ou 27 miles/h |
| 2000 pieds | 13 pieds/s ou 8,8 miles/h | 7,2 pieds/s2 ou 0,22g | 78 pieds/s ou 54 miles/h |
| 1 mile | 23 miles/h | 0,56 g | 135 miles/h |
| 5 miles | 115 miles/h | 2,8 g | 670 miles/h |
| 10 miles | 230 miles/h | 5,6 g | 1300 miles/h |
The objects in the "Utah" and "Montana" films can only be correlated on the basis of two rather weak points. First, their structure, or rather lack of it, is similar. Thus as shown, in the "blow-ups" there are no recognizable differences between them [*The images on the "Utah" film appear to be a little brighter. However, possible variations in development techniques would not allow quantitative analysis in this regard. ]. Second, the objects on the "Montana" film are manifestly a single pair; on the "Utah" film perhaps 30% of the frames show clusters of objects seemingly also grouped in pairs.
The weather report was obtained by the author from the Airport Station at Salt Lake City. The nearest station with available data is Corinne which reported a maximum temperature of 84°, a minimum of 47° and no precipitation. A high pressure cell from the Pacific Northwest spread over Northern Utah during July 2, the pressure at Tremonton would have a rising trend, the visibility good, and the winds relatively light. The absence of clouds and the apparently excellent visibility shown on the films would seem to be in agreement with this report. Through use of References (2) and (3), the Sun's azimuth N132°E altitude 65° was computed. No shadows were available to confirm the time of filming.
The image size being roughly that of the Montana film (a few of the objects being perhaps 10% larger than the largest on the Montana) the same remarks as to airplane reflections apply, i.e., they might have been caused by Sun reflections from airplanes within one to three miles to the observer, although at these distances they should have been identified as conventional aircraft by the film or the observer. No specific conclusions as to Sun reflection angles can be drawn since the line of motion of the objects cannot be confirmed. However, the reported E to W motion of the UFO's and their passing overhead coupled with the SE azimuth of the Sun would make the achievement of optimal Sun reflections rather difficult.
Que les images aient pu être produites par des "paillettes" de feuilles d'aluminum n2[des bouts de feuille d'aluminum jetés par-dessus bord par les avions, souvent utilisées comme contre-mesure contre les radar anti-aériens. Ce matériel pourrait éventuellement être sous forme de grands rubans de plusieurs pieds de long et de plusieurs pouces de large] semble possible, au moins sur la base des images montrées, des reflets spéculaires très intenses de rubans de paillettes pouvant luir jusqu'à la taille approximative des ovnis.
Examination of film frames obtained from the photogrammetric experiment -- reference Analysis of Photographic Material, Serial 01, Appendix II -- show that no significant broadening is produced by flat white diffuse reflectors such as birds, bits of paper, etc. at f/16 under the conditions of the filming. Actual measurements show a slight "bleeding" or flaring of about 10% to 20%.
The rectangular flat white cardboards of the aforementioned experiments represented very roughly the configuration of birds. The light reflected by such a surface is probably greater than that from a curved feather surface of a bird.
One figure shows the appearance of one and 2 foot birds s1[The dimensions refer to wing spread. The actual exposed white area of a bird is usually less and depends upon the perspective of the observer. This difference has been roughly accounted for in the data given, however, if the body were the principal reflector the distance given should be reduced by a factor of 2 or 3] as they might appear on a 16 mm frame taken with a 3" telephoto lens f/16 at a distance of 1,200', at 3,000' and at' 3,300'. Many of the images on the "Utah" film have an angular diameter of 0.001,2 radians (some as large as 0.001,16 radians), thus they might be interpreted as one foot (wing span) birds at 600' to 800', two foot (wing span) birds at 1,200' to 1,600' or three foot (wing span) birds at 2,400' to 3,200'. At these distances, it is doubted if birds would give the appearance of round dots; also they would have been identifiable by the camera if not visually. However, actual movies of birds in flight would have to be taken to completely confirm this conclusion. The following type of gulls have been know to fly at times over this locality: California Herring Gull (a common summer resident), Ring-Billed Gull and-the Fork-Tailed Gull, see Reference (4).
The images are probably not those of balloons as their number is too great and the phenomenon of flaring up to a constant brightness for several seconds, and then dying out again cannot well be associated with any known balloon observations.
Certain soaring insects -- notably "ballooning spiders" (References (5) and (6)) produce bright-moving points of light. The author has witnessed such a phenomenon. It is produced by Sun reflections off the streamers of silken threads spun by many types of spiders. Caught by the wind, these streamers serve as a means of locomotion floating the spider high into the air. They occasionally have the appearance of vast numbers of silken flakes which fill the air and in some recorded instances extend over many square miles and to a height of several hundred feet. The reflection, being off silk threads, is not as bright as diffuse reflection from a flat white board. Thus no flaring of the images could be expected. The author noted that the sections of the "web" that reflected measured from ¼" to ½" for the largest specimens. Thus the images might be attributed to ballooning spiders at distances of 50 to 100 feet. However, these web reflections ordinarily show upon only against a rather dark background and it is doubted if their intensity would be great enough to produce the intense UFO images against a bright sky.
A côté des remarques ci-dessus, pertinent to the actual images, several facts can be gleaned from the motion of objects. The observations are not apt to support the supposition that the objects were conventional aircraft as the maneuvers are too erratic, the relative accelerations probably ruling out aircraft at distances of over five miles. Plusieurs observateurs familiers de l'apparence des paillettes ont vu le film et conclut que la persistance des constellations nontwinkling, leur faible quantité, et l'absence signalée d'appareils au-dessus rendent les paillettes peu probables. De plus, le seul objet passant à travers le champ de vision serait particulièrement difficile à expliquer sur la base de paillettes. Ces mêmes remarques s'appliqueraient aussi à des morceaux de papier swept up in thermal updrafts.
The relative angular velocity might be compatible with soaring bird speeds at distances of less than one mile, the angular velocity of the single object could be attributed to a bird within about one thousand feet. There is a tendency to pan with a moving object -- not against it -- so the velocities in the table probably represent a lower bound. The motion of the objects is not exactly what one would expect from a flock of soaring birds (not the slightest indication of a decrease in brightness due to periodic turning with the wind or flapping) and no cumulus clouds are present which might betray the presence of a strong thermal updraft. On the other hand the single object might represent a single soaring bird which broke away in search of a new thermal -- quite a common occurrence among gulls -- see Reference (7).
That the air turbulence necessary to account for their movement if they were nearby insects (even the single object's motion!) is possible, can be concluded from examination of Reference (8). However, if the objects were nearby spider webs the lack of observed or photographed streamers is unusual. Furthermore, the fact that they were visible from a moving car for several minutes is hard to reconcile with localized insect activity.
The phenomenon of atmospheric mirages, Reference (9), might conceivably account for the images. Such a hypothesis is hampered by the clear weather conditions and the persistence and clarity of the images. Also no "shimmering" can be detected and the motion is steady. Again the object which breaks away would be difficult to explain.
It has been suggested that spurious optical reflections or light leaks in the camera might be responsible. Examples of such effects have been examined and found to be quite different from the UFO's (in the Utah Film).
The evidence remains rather contradictory and no single hypothesis of a natural phenomenon yet suggested seems to completely account for the UFO involved. The possibility of multiple hypotheses, i.e. that the Utah UFO's are the result of two simultaneous natural phenomena might possibly yield the answer. However, as in the case of the "Montana" analysis, no definite conclusion (as to a credible natural phenomenon) could be obtained.
Références
- The "American Nautical Almanac" 1950.
- H. O. No. 214, "Tables of Computed Altitude and Azimuth for Latitudes 40° to 49°."
- J. Veath, J. G. "200 Miles Up," Ronald Press Company, N.Y. Second Edition, 1955, p. 111.
- Kaiser, T. R., "Meteors," Pergamon Press, 1955.
- La Paz, L. "Meteoroids, Meteorites, and Hyperbolic Meteor Velocities," Chapt. XIX of the Physics and Medicine of the Upper Atmosphere.
- 0. G. Farrington, "Meteorites," Chicago, 1915.
- "Measurement of Birds." Scientific Publications of the Cleveland Museum of Natural History, Vol. II, 1931.
- Kartright, F. H., "The Ducks, Geese and Swans of North America," American Wild Life Institute, 1943.
- Headley, F. W. "The Flight of Birds," Witherly and Co., 326 Holborn, London, 1912.
- Menzel, D. H., "Flying Saucers," Harvard University Press, 1953.
- Mees, C. E. K. "The Theory of the Photographic Process," Revised Edition, MacMillan Co., N.Y., 1954.
- Danjon, A., Conder, A. "Lunettes et Telescopes," Paris, 1935.
- Kuiper, G. P., The Atmospheres of the Earth and Planets, University of Chicago Press, 1951.
- Ruppelt, E. J. The Report on Unidentified Flying Objects, Doubleday and Co., 1956.