Brazil.Barra da Tijuca · a magazine's five photos of a flying disc

According to the published account, on the afternoon of May 7, 1952 photographer Ed Keffel and reporter João Martins, of O Cruzeiro, Brazil's most widely read magazine, were at Barra da Tijuca, then an almost uninhabited spot west of Rio de Janeiro, on a routine assignment. At about 16:30 Martins saw an object approaching at great speed from the sea; at first he thought it was an aircraft, until he noticed it was flying sideways.

Keffel had his Rolleiflex camera to hand and, in about sixty seconds, took five photographs: a silent, blue-gray disc with no trail, seen in profile, from below and tilted, over the hills, the sea and a palm tree. O Cruzeiro published them in its May 24 issue, according to the American civilian organization APRO, in a sixteen-page extra supplement, with no mention on the cover or in the index, a sign that it was put together at the last minute with part of the magazine already printed. It was the sensation of the year.

The Brazilian Air Force (FAB) took the photos seriously. A group of officers led by Colonel João Adil de Oliveira, who years later would head the FAB's flying-saucer commission, analyzed them and carried out tests on the ground. According to the account the colonel authorized for release in 1959, his officers went back to the spot several times and tried to reproduce the sequence by throwing a wooden disc into the air and photographing it; they, he said, were the men some witnesses claimed to have seen throwing a disc and taking photos at the same place.

The file preserved in the National Archives contains that work: the five numbered photos, annotated by hand, and a series of technical drawings that reconstruct, for each image, the position of the Sun, the observer's angle of view, the object's height above the sea and its trajectory, as well as a plan of the disc from above, in elevation and in section. The figures place the object between 1.1 and 3 kilometers from the photographer and several hundred meters above the sea.

The report was not made public at the time; it became known on October 11, 1959, when a Bank of Brazil official and enthusiast, Fernando Cleto, presented it on the TV Continental station with the colonel's authorization and argued that those distances demonstrated "the absolute impossibility of a hoax", because a wooden disc cannot be thrown that far. From there the case entered the international UFO literature as one of the best photographic series ever obtained.

The doubts came almost at once. According to the APRO report that defended the photos, months after their publication the US Air Force was already objecting that the shadows on the object ran the opposite way to those of the trees; the same report claimed, without naming them, that other witnesses had seen the object and that the US air attaché in Rio had pronounced the photos genuine. In June 1952 the magazine Ciência Popular argued that the photos were a montage. The journalist Carlos Éboli called them fake. In 1963 the astronomer Donald Menzel and L. G. Boyd, in the book they co-wrote, "The World of Flying Saucers," pointed out the underlying problem: the disc is lit from the left while the palm tree and the landscape are lit from the right; the two flatly labeled the case a hoax.

The Condon Report, the University of Colorado study for the US Air Force published in 1968, included it as number 48 in its catalog and confirmed with its own enlargement that the photos contain "an obvious and simple internal inconsistency". It also noted that the several-kilometer distances in the FAB drawings were not justified, and it rejected APRO's answer (two broken palm leaves would explain the "wrong" shadow) because it does not account for other clumps of foliage showing the same lighting.

In the 1980s further analyses came from the American William Spaulding, the Brazilian Carlos Reis and the Brazilian ufologist Claudeir Covo: in the fifth photo, to produce the shadow visible on the disc, the Sun would have had to be inside the Atlantic Ocean. Covo added that Keffel had only five negatives in the camera and that on them he captured the disc in profile, from above, from below and tilted: too much luck for a one-minute apparition. Menzel and Boyd, and later the 1980s analyses, concluded that the photos were a montage by their own authors; the Condon Report stopped short of calling it a hoax, though it confirmed the lighting inconsistency.

The Brazilian Air Force vouched for a montage. A group of competent officers, with apparent method, produced careful geometry (the Sun, the angles, the heights), but it rested on an assumption nobody checked: that the photos were genuine and the object far away. Everything calculated afterwards inherited that error. The FAB did not cover the case up; it vouched for it. Its file is also the first in the National Archives' UFO collection.

The case also shows how authority circulates. The FAB report became known seven years later, on television, through an enthusiast, and international ufology took it as official confirmation of authenticity; an American civilian organization went as far as presenting it as one of the best photographic series in history. The refutation, by contrast, came from independent critics, an astronomer and a university study, and took decades to prevail. "The Air Force said they were genuine" sounded louder than "the light comes from two sides", even though the latter can be checked by looking at the photo.