Italy.Etna · a drone films something that seems to cross the plume

In December 2018, a forward-looking infrared (FLIR) sensor aboard an uncrewed U.S. Air Force platform was operating over the Mediterranean Sea, near Sicily, while Mount Etna, one of Europe's largest active volcanoes, was erupting. The video, just over twelve minutes long in the version posted to DVIDS on November 19, 2024, shows what appears to be an object passing through the eruption's plume of superheated gas and ash. According to the slide AARO presented to the Senate that day, the object seemed to cross the plume "with no apparent impact to its performance, altitude and bearing", and that was the feature that got it treated as anomalous.

The All-domain Anomaly Resolution Office (AARO) coordinated an "interagency and international analytical effort", in the words of the DVIDS record, with intelligence-community and science-and-technology partners, in the words of the slide. Its director, Jon Kosloski, presented it on November 19, 2024 to the Senate Armed Services Subcommittee on Emerging Threats and Capabilities as "a rather difficult case to resolve", one for which the office even had to reach out to a volcanologist.

The analysis combined full-motion video software, 3D modeling, pixel examination and novel speed and distance calculation techniques. The key test was comparing the luminosity of the object's pixels with a sample of the pixels immediately around it: with it, AARO and its partners disproved that the object flew through the ash plume. The DVIDS record attributes the illusion to optical effects from the intense atmospheric conditions near the volcano, which distorted the video; none of the public sources details the optical mechanism.

The final assessment, at moderate confidence (not high, a nuance the agency itself records) is that the footage shows a balloon drifting at wind speed and direction about 170 kilometers from the volcano. To validate it, AARO used 3D modeling and wind calculations to predict where the object should be when the drone operator lost sight of it, and later video analysis found faint tones of the object exactly along the predicted path. The distance between the object and the drone, by contrast, was not measured: it was estimated from weather analysis of the cloud deck and wind speeds. And the public record is not fully consistent on that figure: the slide and the DVIDS record speak of 170 kilometers from the volcano or the caldera, while Kosloski, in his oral testimony, said the object was "170 meters away from the plume".

The central problem is one of geometry and imaging: deciding whether an object that overlaps a volcanic plume is inside it or far away, in front of it or behind it. That AARO needed intelligence and science-and-technology partners plus a volcanologist, and that its director called it "a rather difficult case to resolve", indicates the illusion was convincing on screen.

AARO gave this assessment moderate confidence, not high. A balloon 170 kilometers away drifting with the wind has a verified prediction in its favor (the faint tones found where the model said the object would be), but the distance rests on a weather estimate rather than on an independent cross-check such as an air traffic record. The discrepancy between the written 170 kilometers and the 170 meters spoken at the hearing is probably a slip of the tongue, but the public record of the resolution is brief, and its main piece, the full report hosted on aaro.mil, is not among the sources cited. "Resolved by AARO" is not a single level of certainty: the agency grades its confidence case by case.

According to AARO's assessment, the error came from the line-of-sight overlap of a distant object with the plume of an active eruption, made worse by its extreme atmospheric conditions. Without the geographic and meteorological context, that overlap read as an object passing unperturbed through the ash plume.