Type: Radar Data
Source:
Ground-controlled intercept radar operators at Ellsworth Air Force Base tracked an unidentified target that corresponded with visual reports from ground observers and interceptor aircraft.
The Ellsworth Air Force Base UFO Incident, occurring on August 5, 1953, is a prominent radar-visual case where military radar and multiple eyewitnesses tracked an unidentified object over South Dakota and North Dakota. The object, described as a bluish-white or red glowing light, was first reported by a civilian spotter in Black Hawk, SD, and immediately confirmed on Air Defense Command radar at 16,000 feet.
Two F-84 Thunderjet interceptors were scrambled to pursue the object; each time a jet closed within approximately three miles, the object accelerated to maintain the gap, exhibiting behavior likened to an automatic proximity avoidance system. The object outran the jets for over 120 miles before disappearing over the horizon, with additional sightings recorded as far as Bismarck and Fargo, North Dakota.
Investigated personally by Project Blue Book director Captain Edward J. Ruppelt, the incident is classified as unexplained due to the convergence of ground radar, height-finding radar, visual sightings by military and civilian observers, and pilot intercepts. Although radar scope photos were reportedly taken, a camera malfunction prevented their development, leaving the corroborated witness testimony and radar data as the primary evidence for this Cold War-era encounter.