Mt. Etna Spherical Object, 2018
UAS operators tracked a round object transiting volcanic ash plume at high speed.
Dec 1, 2018
Pending
All-domain Anomaly Resolution Office
AI Disclosure Brief
AI assistedReported Object Read
A round/spherical object appeared in SWIR video from a U.S. military UAS, seemingly moving at high speed through Mt. Etna's ash plume without effect.
Notable Characteristics
- Size: 0.3 meters (1 foot) diameter
- Altitude: 15,000 feet (assessed)
- Duration: 4.5 minutes
Reported Motion
- Slow drift with wind, apparent high speed due to motion parallax
Evidence Notes
- SWIR video footage
- 3D modeling
- Pixel examination
AARO's detailed analysis attributes the apparent high-speed transit to motion parallax, sensor limitations, and atmospheric effects, resolving to a likely balloon with no anomalous behavior.
Sphere
SWIR (Shortwave Infrared)
80%
Prosaic Leads
- Balloon drifting with wind
- Motion parallax from UAS motion
- SWIR sensor limitations in turbulent conditions
Anomalous Indicators
- Initial operator perception of high speed and plume transit
Evidence Gaps
- No active range-finding data
- Sensor optimized for air-to-ground, not air-to-air
- Atmospheric turbulence effects
Evidence Quotes // source statements
Open archive"AARO assesses with moderate confidence that the object was a balloon. AARO assesses with high confidence that the object did not exhibit anomalous behavior."
Unknown speaker, AARO Assessment / All-domain Anomaly Resolution Office
AARO Assessment and Case Status
Source"UAS operator reported object's speed as approximately 555 kph (345 mph), seemingly unaffected by transiting the plume."
Unknown speaker, Reporter / U.S. Military UAS operators
Case Overview
SourcePattern Mesh // linked sightings
Go Fast FLIR Object Off Florida, 2015
Navy pilot's infrared video shows object at 13,000 feet moving with wind, not anomalous speeds.
Same source archive
Shared tags: case-resolution, motion-parallax
Puerto Rico Infrared Objects, 2013
AARO resolves CBP thermal video of drifting objects as likely sky lanterns.
Same source archive
Shared tags: case-resolution, motion-parallax
Eglin Pilot's Cone-Shaped UAP, 2023
Military pilot tracked four radar objects, visually closing on rounded cone at 16,000 feet.
Same source archive
Shared tags: case-resolution, balloon
Western US Equidistant Lights, 2021
Military sensors captured five lights resolved as distant commercial aircraft.
Same source archive
Shared tags: case-resolution
Southeast Asia Triangles Resolved as Fishing Nets
AARO resolves 2017 satellite imagery of six dark triangles as static cone-shaped fishing nets.
Same source archive
Shared tags: case-resolution
Atmospheric Wakes Over Middle East, 2022-2023
UAV operators reported potential anomalous propulsion signatures resolved as sensor artifacts.
Same source archive
Shared tags: case-resolution
Chronology Trace // before & after
No dated sibling signals are available yet.
Official Files // source material
1 linkedMt. Etna Case Resolution
UNCLASSIFIED 1 UNCLASSIFIED All-domain Anomaly Resolution Office U.S. Department of Defense Case: “Mt. Etna Object” Case Resolution | 28 April 2025 Case Synopsis Location: Mt. Etna, Italy Date: December 2018 Object Altitude (reported): 500 feet Object Altitude (assessed): 15,000 feet Object Speed (reported): 345 mph Object Speed (assessed): 24 mph Object Shape (reported): Round Object Shape (assessed): Spherical Reporter: U.S. Military UAS operators Data Type: Infrared Reported Behavior: An object moving at high speeds through Mt. Etna’s ash plume. Assessed Behavior: The object did not demonstrate anomalous performance characteristics. Confidence: Moderate confidence the object was a balloon. High confidence the object did not demonstrate anomalous pe