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Mt. Etna Object Case Resolution

All-domain Anomaly Resolution Office · 5 pages · text from the file's own layer

This case resolution from the All-domain Anomaly Resolution Office of the U.S. Department of Defense is dated 28 April 2025. It examines a December 2018 infrared video recorded by a U.S. military uncrewed aerial system near Naval Air Station Sigonella. The object appeared to move at high speed through the ash plume of an erupting Mt. Etna. AARO has moderate confidence that the object was a balloon about one foot across, drifting at wind speed about 30 km from the sensor. It concludes that motion parallax and sensor limits created the appearance of anomalous behavior.

UNCLASSIFIED
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UNCLASSIFIED
Figure 2: AARO’s top-down reconstruction of the event depicting the object’s distance from the
UAS platform. (not to scale)
Observable Characteristics and Attribution
Size and Shape: AARO employed pixel examination to conclude with moderate confidence that
the object was spherical. Its approximate diameter was 0.3 meters (1 foot). (Figure 3)
Attribution: Due to the object’s size and performance characteristics, AARO assesses with
moderate confidence that the object is a balloon.
(UNCLASSIFIED)
(UNCLASSIFIED)

Cases discussed

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Analysis, from the aaro collection. The PDF is mirrored here; the original link is above. 5 pages are in the text index: search them above, or from the library's search.