Approx 200 Mi south of New Orleans, LouisianaNovember 1957

On November 5, 1957, the crew of the Coast Guard cutter Sebago reported radar and visual contacts with an unidentified object roughly 200 miles south of New Orleans, Louisiana. The ship was steaming north in the Gulf of Mexico when its radar first picked up a target at 0512 hours (12:12 a.m.) bearing 290 degrees true, 14 miles away. The target moved from north to south, then reversed course and closed to within two miles of the ship. Over the next few minutes, the radar crew made three additional contacts, sometimes seeing the target hovering in place and other times observing it fly in what appeared to be a circular pattern.

At 0521 hours (12:21 a.m.), the ship's crew caught their only visual glimpse of the object. It appeared as a brilliant point of light, resembling a bright planet. The object moved horizontally from south to north at high speed, remaining visible for approximately three seconds as it passed through a bearing arc from 270 to 310 degrees. The entire sequence of radar and visual events lasted about six minutes before all contact was lost.

Air Force investigators examined the Sebago's reports and concluded that the radar contacts were most likely anomalous propagation, a phenomenon in which radio waves bounce off atmospheric layers to create false target returns on radar screens. This effect can be particularly pronounced in the Gulf of Mexico, where warm ocean air meets cooler upper atmosphere layers. The visual sighting, the investigators determined, was probably a meteor. They noted that the impression of a single mysterious object was erroneous, since the radar targets kept appearing in nearly opposite directions at considerable distances from one another, a pattern inconsistent with a single craft maneuvering in the area.

The complete case file, consisting of 9 pages as held by the National Archives, is reproduced below.