Uraguay, October 1958October 1958

In October 1958, a resident of Uruguay reported seeing a luminous, oval-shaped object moving over a small town. The witness, who looked outside after hearing noise from the street, described the object as glowing white with a yellowish tint. It moved in all directions, rising and falling with an oscillating or swaying motion. The witness also saw red, blue, and green lights that traveled around the central white glow. A horizontal protrusion resembling smoke extended from one end of the object.

The object's behavior was erratic. It moved in straight lines and made sudden turns, changing speed rapidly. At times it climbed to about 35 degrees above the horizon before moving away in a slow, straight path in the opposite direction from where the witness stood. The entire sighting lasted about 25 minutes.

The Uruguayan Air Force intelligence service (CIOVI) investigated the report and found the witness's account complete and consistent with documented characteristics of earlier sightings. The investigators noted the oval disk shape, the oscillating movement, the ascents and descents, and the colored lights moving around the central luminosity as distinctive features. They concluded the sighting represented a flying saucer, though they acknowledged that such objects could appear without any visible lights.

A separate report in the U.S. Air Force file describes a different sighting on the same date, when a civilian controller at a U.S. radar facility spotted a large, cone-shaped, shiny bright object at altitudes between 15,000 and 20,000 feet. That object remained stationary for approximately 40 minutes. The Air Force determined that a weather balloon released from Minnesota on October 12 with a 120-foot length and clear plastic construction could account for that sighting, based on wind patterns aloft.

The full case file is reproduced below as held by the National Archives, comprising 12 pages.