The Socorro landing (Lonnie Zamora)

On the evening of 24 April 1964, Sgt. Lonnie Zamora of the Socorro police broke off a traffic pursuit to investigate a roar and a cone of flame descending toward a dynamite shack south of town. Approaching on foot, he saw a whitish egg-shaped object on girder-like legs in the arroyo, and beside it two small figures in white coveralls, one of whom appeared to startle at his presence. As he retreated to his car to radio in, the object rose on a column of flame, went silent, and receded at speed. Deputy Sam Chavez arrived within minutes to find Zamora shaken, the brush burning, and four wedge-shaped landing depressions pressed into the soil.

The investigation was immediate and, by the era's standards, thorough: the FBI's Albuquerque office was on scene that night, and Blue Book sent both Maj. Hector Quintanilla and consultant J. Allen Hynek. Soil and burn analysis found no chemical propellant residue. Quintanilla, who considered a classified lunar-lander test the likeliest answer, ran the possibility to ground and eliminated it — no test vehicle was operating in the area. Blue Book closed the file as unidentified, and it stayed that way at the project's 1969 closure.

Later proposed solutions — a New Mexico Tech student hoax recounted secondhand decades on, a misperceived Surveyor test — have been argued and none established; Hynek, initially inclined toward the hoax hypothesis, investigated and abandoned it. Socorro remains the case Blue Book's own chief called the best-documented in the files: a single close witness of good reputation, physical traces photographed the same night, and an official unknown on the record.