DOW-UAP-D102: Project Blue Book File on Tremonton Film, Utah, 1952

white; no strong colors are notea. As to similar motion, a definite grouping
of objects is noticeable. The first two sequences, taken with the slcy as a
light blue , show what probably are two groups of three objects each, and two
groups of two each. The final sequence, against the dark blue slcy, shows four
pairs of objects, with the fifth pair having drifted upwards , out of the camera' s
field of view.
6. If the objects are reflecting, the 11fade-in11 and fad.e-out 11 are caused
by changes in attitude of decidedly non-spherical objects, as in .Answer 1 above.
On the other hand, if they are light sources, the variation could be associated
with their maneuvering activity.
7. and 8 . As explained in the o'Oening paragraph, the objects are only
small bright s-oots on the film. When they dim sufficiently, they become invis
ible ; no dark spots can be identified with these objects. The only visible
motion in any single frame is with respect to the camera's field of view. Slow
motion examination of successive frames suggests a general flight pattern of
sweeping skew curves in space. This concept of object motions -produces no sharp
breaks in their apparent flight paths , and also makes it practically impossible
to detect rapid accelerations or decelerations along these patns.
9. In the seouences during which the camera \\'as held motionless , to record
the angular velocity of a single object, it is possible to measure this velocity.
Three such passes can be seen. Tae first was incomplete, picking up the object
near the center of the frame . The second and. third passes were complete, from
one ec..ge of the field of view to the other.
J?i;..";tll'e I shov,s the actual tracings of the object from frame to frame for
both Passes No. 2 and No. 3. The distance from lens to screen ~,as 100 inches.
The focal length of the projection lens \.,as 2 inches. The enlargement of
Figure I over the actual negative size is therefore 50 times. Camera and pro
jector errors, plus small band- held camera motions , probably account for the
deviations from a straignt line path. The average calculated angular velocity
for both paths is about 2.1 degrees per second. Detailed computations are given
in Append.ix I.
10a. A slow motion viewing, plus single frame position plots, suggest that
the objects are maneuvering in definite formations. However, successive identical
positions are not indicated when position plots from any t~o frames in a sequence
are superimposed. For instance, the first sequence of movement lasts 160 frames
or 10 seconds. During the first seven seconds, clear plots for all 10 objects
can be made. These plots were made at half second intervals or 8 frames apart.
10b. Figure II represents a possible set of flight paths for this interval,
derived as explained in Appendix II. It should be remembered that Figure II
very likely contains some indeterminate and non-constant camera motion, botn
horizontal and vertical, caused by tracking the formations . This means th?.t the
directions and curvatures as sho1:-m may be a9oreciably different from ,,·bat a
--stationary camera would have recorded. However , Figure II does help visualize
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DECLASSIFIED Authority NND 923007