United States & Canada, August 1957August 1957

In mid-August 1957, people across the United States and Canada reported seeing a bright, moving object in the night sky. The sightings spanned several days and involved multiple witnesses in different locations, including observers in Wyoming and New York.

The witnesses described the object as appearing like a bright star, white or silver in color, with a long, narrow tail stretching across the sky. Some observers noted it was roughly two to three degrees wide, or about two to three times the width of the moon. The object moved slowly westward across the sky and eventually faded from sight. In one report, an observer in Albin, Wyoming, watched the phenomenon for about three minutes during dusk, while a woman in Newburgh, New York, saw it around the same time. A third witness, an amateur astronomer, noted wind drift as the object moved through the sky.

The Air Force gathered weather data and wind information from multiple altitudes to help evaluate the sighting. Officers interviewed witnesses and reviewed local radio news reports that mentioned a possible comet in the area. Captain Stephen M. Flanagan, an operational intelligence officer, concluded that the object was likely a comet that had been visible in the sky for several nights before the reports came in.

The case file lists the Air Force's final evaluation as "probably balloon" on the cover sheet, though the investigating officer's remarks and comments within the file suggest a comet identification. The full case file, consisting of 13 pages as held by the National Archives, is reproduced below.