Project Blue Book Case File
Bill, WyomingDecember 1957
Summary
On December 22, 1957, a resident of Bill, Wyoming saw a bright ball of fire streak across the sky and fall to earth roughly a quarter mile away. The object had a greenish color and appeared to be descending toward the ground.
The Air Force received a detailed written account of the sighting from the witness, a cooperative weather observer in the area. The report was forwarded through official channels to the Air Force's Office of Information Services for analysis.
Major Lawrence J. Tacker of the Air Force responded to the witness on February 24, 1958. He concluded that the sighting was almost certainly a fireball, also known as a bolide, a type of exceptionally bright meteor. The greenish-white coloring and other characteristics matched known bolide sightings, and similar events had been reported in Wyoming the previous year. The Air Force marked the case as "Probably Balloon," though the official correspondence indicates the analysis pointed to a natural atmospheric phenomenon.
The full case file, consisting of 7 pages, is reproduced below as held by the National Archives.
Reported location
Bill, Wyoming
Date of incident
December 1957
State / country
WY / US
Page count
7 scanned pages
USAF evaluation
unknown
Microfilm
T1206, Roll 31