Project Blue Book Case #1256. On June 5, 1952, yet another unidentified object was observed over Albuquerque — the sixth Blue Book unknown from the nuclear corridor, coming just eight days after the fifth (Case #1233). The rapid-fire occurrence of two unknowns in barely a week over the nation's most sensitive nuclear weapons complex represented an extraordinary concentration of unexplained activity.
Six cases from a single city — spanning the green fireball era through the great 1952 wave — made Albuquerque the undisputed leader in Blue Book unknowns among all American cities. The case was classified "Unknown."