Project Blue Book Special Report (second copy)

This is Project Blue Book Special Report No. 14, "Analysis of Reports of Unidentified Aerial Objects," Project No. 10073, dated 5 May 1955. The study reduced about 4,000 sighting reports received by the U.S. Air Force between June 1947 and December 1952 to IBM punched cards and analyzed them statistically, including chi square tests comparing knowns with unknowns. It concludes that the reports very probably do not represent technological developments beyond present scientific knowledge, and it notes that no case produced physical evidence.

i
r
c
o
Ik.
0>
CL
100
90
80
70
60
50
40
30
20
10
Unknown
_lnsuf. _
- i n f o . ~
Balloon
Aircraft
vAstro-
nomical
White
23.5%
100
90
80
70
60
50
40
30
20
10
c
a>
O
V.
a.
Metallic
17.7%
Not
stated
12.3%
Orange
10.0%
Red
8.1%
Other
2 8 . 4 %
FIGURE II DISTRIBUTION OF OBJECT SIGHTINGS BY REPORTED COLORS
OF OBJECTCS) WITH EVALUATION DISTRIBUTION FOR EACH
COLOR GROUP
f A-7469
27