Argentina.Campo de Mayo · the Gendarmería Cessna's coloured sphere

On the evening of 2 November 1972, an Argentine Gendarmería Nacional Cessna 182 was flying a night training sortie over Campo de Mayo aerodrome, north-west of Buenos Aires. At about 20:30 its crew, led by the then officer and later commander Héctor Ramón Flores, saw a large luminous object to the north-west, on a bearing of 320° and some 25° above the horizon. The crew described it as a huge sphere, almost a balloon or a cloud of incandescent gas, with bands of colour: red at the top, a violet stripe in the middle and blue below. During the observation the sphere changed shape; in the final phase, over the town of Campana, it seemed to them to make a sharp turn of almost 90° and to take on the shape of a solid object. Reading it as a collision threat, the pilots spiralled down in an evasive manoeuvre and, by their own account, made an emergency landing. The object gradually faded until it disappeared.

The crew took no photographs, but they left written statements and a series of colour drawings made on the ground that record the sequence. All of this went into a Gendarmería file that stayed in its archives for more than forty years, until in 2015 a civilian enthusiasts' group, CEFORA, published it on its website. Because of the witnesses' professional standing and the precision of their drawings, the case came to be counted among the most enigmatic in Argentine case history.

In February 2017 the group's secretary, Luis Brussa, consulted the Argentine Air Force's aerospace phenomena commission (CEFAE, now CIAE) and pointed out that a balloon and an experimental rocket had been launched that day from Chamical air base in La Rioja. The commission, headed by Commodore (ret.) Rubén Lianza, published its analysis in its 2017 annual report under the heading 'Enigmatic cases never resolved before'. It found that a Rigel sounding rocket had lifted off from Chamical on 2 November 1972 at 23:28 GMT —20:28 local time—, with the mission of releasing a barium cloud before its apogee, at about 240 km. The historical launch record lists that flight as an aeronomy and ionosphere mission. Seen from Campo de Mayo, the patch of sky where the cloud was matched the bearing and elevation the crew reported.

In 2018 the commission extended the work with the original launch document, Report EANI 1/72 on Rigel 05. At a launch angle of 87°, the rocket reached the barium injection altitude, 170 km, two minutes after lift-off; the planned time was 20:25, and Commodore Luis Cueto, who signed that report, confirmed to the commission that a last-minute adjustment could have delayed it to 20:28. The colour arrangement the pilots drew matches that of ionised barium clouds recorded on video. For the final turn, which Flores maintained in a telephone conversation, the commission proposed that the cloud, pushed east by ionospheric winds, was deformed on meeting the edge of the South Atlantic Anomaly, right over Campana. The CIAE's 2025 report reaffirmed the conclusion and added a late witness who, as a child, saw the cloud from Santa Fe to the west-north-west, towards Chamical: a distant observation consistent with a phenomenon hundreds of kilometres up, not with an object beside the aircraft.

Campo de Mayo is an exemplary case on the resolved side of the corpus, and for that reason it is worth as much as an unexplained one. It had everything that usually lends weight to a sighting: professional witnesses in flight, an official file from a security force, detailed drawings, a real evasive manoeuvre and four decades of mystery. And yet the explanation lay in another archive of the same state: that very day, from Chamical, Argentina's space programme launched a rocket that released barium clouds to study the ionosphere. The match is not vague: the launch time, two minutes before the sighting; the patch of sky, which fits the reported bearing and elevation; and the sequence of colours, which reproduces that of ionised clouds.

The methodological lesson is twofold. First, the perception of closeness deceives: a cloud 170 or 240 km up, lit by the Sun when it is already night on the ground, can look huge, close and threatening to a crew with no frame of reference, who read it as a self-propelled object. Second, the scientific and military experiments of the era —barium, sodium or strontium clouds, sounding rockets, stratospheric balloons— are a source of sightings that can only be detected by cross-checking case files against launch records. It is the same mechanism that explains the Norwegian spiral of 2009 or the Chinese one of 1981, and here it is documented with the launch's original technical report.

The case's partition therefore puts almost all the weight on the misidentification of a space experiment. It leaves an undetermined margin for the final turn, which the South Atlantic Anomaly hypothesis explains plausibly but does not prove. For the corpus, it also fills a real gap —Argentina in the 1970s— and shows the Argentine Air Force doing what is expected of a serious office: reopening someone else's file, looking for the cause in verifiable records and publishing its reasoning under an open licence.