Project Blue Book Case #2155. On October 10, 1952, air defense personnel at Otis Air Force Base on Cape Cod, Massachusetts, tracked a bright object in the sky above the base. Otis AFB was a key Air Defense Command installation, home to interceptor squadrons tasked with defending the northeastern seaboard — including Boston and the vital New England industrial corridor — from Soviet bomber attack.
The base's position at the tip of Cape Cod gave it a commanding view of the Atlantic approaches, and its radar systems provided early warning coverage over a vast expanse of ocean. Personnel were trained to detect and identify any aircraft entering the northeastern air defense identification zone, making their report of an unidentified object particularly significant.
October 1952 came in the aftermath of the great summer wave, and Blue Book was still processing the backlog of cases from July and August. The rate of new reports had declined from the summer peak but remained elevated compared to pre-wave levels. Cases from air defense installations continued to receive priority attention.
The object tracked at Otis exhibited characteristics inconsistent with any known aircraft type. Its brightness and movement pattern did not match scheduled military or civilian flights in the Cape Cod area. The base's radar and visual observation capabilities made false identification unlikely.
All air defense sector flight records were checked with negative results. The case was classified "Unknown."