Project Blue Book Special Report (second copy)

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UNKNOWNS with sufficiently detailed description would be called "good
UNKNOWNS", while the remainder would simply be called UNKNOWNS.
One hundred sixty-four folders of a total of 186 OBJECT SIGHTINGS in
Groups 1, 2, 3, 6, and 7 were examined. There were 18 possible aircraft,
20 possible balloons, 7 good UNKNOWNS, 100 UNKNOWNS, and (19 others
which were identified as being possible KNOWNS of various types. It is
interesting to note that two of these were established as mock suns on the
basis of the angle of sun elevation and the sun bearing angle, together with
the direction of the object from the observer. In addition, the UNKNOWNS
in angle-of-sun-elevation Groups 4 and 5 (nighttime sightings) were scanned
with no attempt at identification, but to find any possible "good UNKNOWNS",
There were five sightings that could be put into this category.
Of the UNKNOWNS, there were approximately 20 sightings that were
observed in such a way that they should have been recognized easily if they
had been familiar objects, that is, there was little possibility that their
shapes, as seen, could have been distorted sufficiently by one cause or
another to render them unrecognizable. There were a very few that would
have been identified as guided missiles or rockets, but that were not so
identified because of the geographical location in which they were seen.
All of the remaining UNKNOWNS were classified as such solely be-
cause they were reported to have performed maneuvers that could not be
ascribed to any known objects. In these cases, the shape might have been
unrecognizable also, but it was felt that this was because of distortion and
distance, or'because of darkness.
This is a very important point. To put it differently, if these
UNKNOWNS, which represent all but about 40 of the UNKNOWN SIGHTINGS,
were reported to have performed maneuvers which could be ascribed to
known phenomena, they would probably have been identified as KNOWNS.
With the exception of some radar sightings, all of these maneuvers were
observed visually. The possibilities for inaccuracies are great because
of the inability of an observer to estimate visually size, distance, and
speed.
Reports of sightings by radar usually were of high-speed objects,
some at extremely high altitudes. Some were identified as UNKNOWNS
because there was no object to be seen visually at the point indicated by the
radar seto It cannot be said wrth any assurance what these radar sightings
mean, but the most logical explanation is that they are ground targets re-
flected by an atmospheric temperature inversion layer. The validity of this
statement cannot be established. It is felt that radar sightings in this study
are of no significance whatsoever unless a visual sighting of the object also
is made. ,
Taken in conjunction with the Chi Square Tests discussed earlier,
the results of the re-evaluation of reports identified as UNKNOWN
SIGHTINGS would seem to indicate that the majority of them could easily
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