Arcata, CaliforniaApril 1960

Unidentified

Summary

On April 9, 1960, a man in Arcata, California, was taking photographs of the setting sun through an 8-inch telescope when an unusual object appeared on the negative. When the film was developed, a round, dark spot was visible between the camera and the sun, roughly the size of Venus or Mercury as seen from Earth.

The witness reported the sighting to officials at Hamilton Air Force Base in California, along with the photograph and negatives. He described the object as comparable in size to Venus or Mercury, though he noted it could not be a heavenly body based on its position relative to the sun. The Air Force forwarded the case to the Aerospace Technical Intelligence Center (ATIC) at Wright-Patterson Air Force Base for analysis.

Experts at ATIC, including personnel from the Photo Processing Branch and Equipment Support Branch, examined the photograph carefully. They considered several possibilities: whether the object was in focus, out of focus, a particle in the air between the telescope and the sun, or even a defect in the film's emulsion. The analysis noted that the telescope had a resolving power of about 567 arcseconds (a measure of how finely detailed objects the scope could distinguish). The investigators studied how light interacts with circular telescope lenses and how stars appear as small discs surrounded by rings of light due to the wave nature of light.

In their conclusion, the analysts determined the spot was most likely a defect in the film's emulsion, similar to flaws they had seen many times before in photographs. The sun's distortion in the vertical direction at sunset, caused by atmospheric refraction, would have been visible on the image if the object were real. Its absence supported the defect explanation. The Air Force evaluation for this case is listed as unidentified, though the technical analysis strongly suggested a photographic artifact rather than a genuine anomalous object.

The full case file, consisting of 27 pages as held by the National Archives, is reproduced below.

Reported location

Arcata, California

Date of incident

April 1960

State / country

CA / US

Page count

27 scanned pages

USAF evaluation

unidentified

Microfilm

T1206, Roll 38

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