Project Blue Book Case File
Sacramento, CaliforniaSeptember 1952
Summary
On September 3, 1952, observers at a Ground Observer Corps post near Sacramento, California reported seeing a fast-moving, disc-shaped object with a dark line through its middle. The sighting lasted only an instant. The observers watched the object through binoculars from their position about three miles west of the post, as it traveled northward across the clear sky.
According to the case file, a military airplane had passed over the area shortly before the object was sighted. The file notes that the observers spotted the object very briefly, leaving few details about its behavior or appearance beyond its general shape and dark coloring.
The Air Force's investigators marked this case as "unidentified" in their formal evaluation. The brief nature of the sighting and the limited information gathered meant that no firm conclusion could be reached about what the observers had seen. The full case file is reproduced below as held by the National Archives, consisting of 10 pages.
Reported location
Sacramento, California
Date of incident
September 1952
State / country
CA / US
Page count
10 scanned pages
USAF evaluation
unidentified
Microfilm
T1206, Roll 15