Thule Air Base Greenland Encounter 1960

On June 4, 1960, Thule Air Base in Greenland — the northernmost US military installation and home of the Ballistic Missile Early Warning System (BMEWS) designed to detect Soviet ICBM launches — was overflown by an unidentified luminous orb at extremely close range. Security personnel and BMEWS radar operators observed the craft hovering at 500 feet above the massive BMEWS radar installation for 25 minutes. The craft was visible from multiple points on the base and created significant disruption. Given Thule's critical national security role — the BMEWS station was literally the country's primary nuclear attack warning system — any security intrusion triggered the highest possible alert classification. A special Joint Chiefs FLASH message was filed documenting the incident. NORAD initiated a full alert investigation. The proximity of the object to the BMEWS radar arrays raised concerns about intelligence collection capability. The incident was classified under the most restrictive Special Access Programs protocols and few references to it survived declassification reviews.