UNCLASSIFIED

All-domain Anomaly Resolution Office
U.S. Department of Defense(U) Case: “Eglin UAP”
Case Resolution | 14 October 2023

(U) Case Background(U) On 26 January 2023, a military pilot reported
four potential unidentified anomalous
phenomena (UAP) while operating in the Eglin
Air Force Base training range off the coast ofFlorida. Through the onboard radar system, thepilot initially observed that the four objects werealoft between 16,000 – 18,000 feet and appeared
to be flying in formation. However the pilot
observed only one of the four objects visuallyand captured two images of the single object via
the aircraft’s electro-optical/infrared (EO/IR)
sensor (see Figures 1A and 1B). The pilot could
not record video of the event because theaircraft’s video recording equipment wasinoperable prior to and during the aircraft’sflight. The pilot observed this single object aloft
at 16,000 feet. The following case information isbased on the pilot’s initial report and asubsequent discussion that AARO held with thepilot to seek additional details about the pilot’s
observation of the reported object.

(U) Case Essentials(U) A military pilot reported the object
due to its potential as a flight safety
hazard and an incursion into a sensitive
training range(U) Location: Near Eglin Air Force Base,Florida(U) Date: 26 January 2023
(U) Altitude: 16,000 feet(U) Shape: Rounded, cone(U) Reporter: Military personnel(U) Sensor: Electro-optical, infrared,
visual identification, and radar(U) Behavior: No confirmed anomalous
behavior(U) Case Status: Resolved; very likely alighter-than-air object, such as a largecommercial lighting balloon• (U) The pilot described the object as gray(U) Confidence Level: Moderatewith a paneled surface and orange-red
coloring at the center. The initial report
did not provide the object’s size and speed, but in the subsequent discussion with AARO,
the pilot reported the object was about 12 feet in diameter and that it either moved very
slowly or was potentially stationary.
• (U) In the initial report, the pilot described the bottom half of the object as being rounded,and the top half as a rounded, three-dimensional cone shape, similar to the shape of the1
UNCLASSIFIEDUNCLASSIFIED“Apollo spacecraft” (see Figure 2). The pilot visually perceived a heat signature emanatingfrom the rounded bottom portion, which they described as “blurry air.”• (U) During AARO’s discussion with the pilot, the pilot stated that they thought they saw avertically oriented engine affixed to the side of the object that was nearly the height of theobject. This feature is not visible in the two still images taken by the EO/IR sensor, and thepilot did not include this description in the initial report. AARO has no additional data tocorroborate whether the object may have had an engine.
• (U) The pilot reported that upon closing to within 4,000 feet of the object, the radar on theaircraft malfunctioned and remained disabled for the remainder of the training exercise.
Post-mission review determined that a circuit breaker had tripped; technicians reported
that the same circuit breaker on this particular aircraft had tripped three times in the priormonths, but technicians could not conclusively diagnose the cause of the fault for thisincident. Based on the previous tripping of this circuit, AARO assesses the malfunction
likely was not caused by or associated with the object.
• (U) During the discussion with the pilot, they recounted that after the radar malfunctioned,
the object descended into the cloud deck.
• (U) There was no EO/IR data for the other three reported objects initially observed onradar; therefore, AARO could not analyze those reported objects.

(U) Key Findings(U) AARO assesses the reported UAP very likely was an ordinary object and was not exhibiting
anomalous or exceptional characteristics or flight behaviors. AARO has moderate confidence inthis assessment due to the limited data provided.
• (U) AARO assesses the object was a lighter-than-air (LTA) object, such as a large formfactor balloon; a meteorological balloon; a large Mylar balloon; or a large, commercial,outdoor, helium-filled, lighting balloon. AARO has moderate confidence in its
identification of the object. AARO bases this assessment on a thorough review of the datacollected, official pilot accounts of the object’s description and behavior, laboratory testingof a commercial lighting balloon determined to have similar physical characteristics to theobject described in the pilot’s report, a reconstruction of the flight geometry, and the sunangle at the time of the observation.
• (U) No anomalous flight characteristics, behaviors, or capabilities were confirmed. AARO
assesses the circuit breaker trip that caused the radar to fail was coincidental and likely
due to a pre-existing, undiagnosed technical problem with the system.
• (U) The physical description of the UAP was generally consistent with an LTA object held
aloft and carried by the wind; its direction and reported slow speed are consistent with thewind direction and speed at the time and the altitude of the observation.

2UNCLASSIFIEDUNCLASSIFIED• (U) The “blurry air” observation could have been a visual misperception due toenvironmental conditions and potentially resulted from a tether hanging below the LTA
object or motion-induced image blurring.
(U) Although the pilot described the object as uniformly gray in the visible spectrum (it appears
uniformly black from the viewing angle in the EO image), the magnified infrared image shows
the object had a strong contrasting signature in the infrared spectrum. This contrast suggests
either a temperature/emissivity difference or a reflectivity difference between its twohemispheres. AARO identified a commercial lighting balloon (see Figure 1C), which is a close
visual match to the object in the zoomed-in infrared image (see Figure 1A). Commercial helium
balloons such as these are often large and available in many shapes — including ellipses,
spheres, and cylinders — and are used for outdoor lighting at special events, construction sites,
and movie sets. Although these balloons are available in solid colors, some models have distinct
black and white hemispheres. The upper black hemisphere is lined with reflective material todirect the light downward through the white hemisphere. AARO conducted extensive testing
using one of these balloons and found it could replicate some aspects of the pilot’s account.
• (U) The balloon’s hemispheres have seams resembling the ribbed fabric panels of anumbrella, which an observer could perceive as “paneling.”• (U) These balloons are publicly available to rent or buy. Although the balloons are
powered by corded alternating current (AC), during its testing, AARO determined that they
can be converted to direct current or AC battery power.
(U) Beyond these commercial lighting balloons, the object’s description correlates with anylarge-form balloon that might be made of two different materials, or the same material ofdifferent colors, with distinct infrared reflective or emissive properties. It is also plausible thatthe sun angle at the time of day of the event, when plotted with the EO/IR sensor’s viewing
angle, illuminated the bottom half of the balloon — from the pilot’s perspective — while the top
would appear dark, shaded, and cold (See Figure 3).
• (U) Due to the angle of the sun and the altitude of the object, a meteorological or Mylarballoon likely would also present in a similar fashion on an EO/IR image. The highlyreflective surface of a Mylar balloon in infrared would exaggerate the perceived
illumination effect.
(U) AARO submitted the case for review to an Intelligence Community (IC) component and ascience and technology (S&T) partner; these two partners independently reached highconfidence assessments that the object did not exhibit anomalous characteristics or behaviors
and, therefore, was an ordinary object. Both partners independently determined that the object
very likely was some form of balloon.

3UNCLASSIFIEDUNCLASSIFIED(U) Intelligence Assessment(U) AARO’s IC partner on this case assesses with high confidence that the object was notexhibiting anomalous characteristics based on the available data and its reconstruction of theevent. Available data included the altitude, geocoordinates of the object, the aircraft viewing
angle and heading, as well as the sun geometry at the time of the observation.
• (U) Based on reconstruction of the event, to include the viewing angle of the EO/IR sensor
that took the zoomed-in image, the sun would have illuminated the bottom hemisphere ina manner consistent with the IR image (see Figure 3). The orange-red color at the centerof the bottom half of the object could be explained by the sun glint off the object as thepilot observed it, thus causing the appearance of the orange-red colors on the balloon.

(U) Science & Technology Assessment(U) AARO’s S&T partner independently came to the same general conclusions based on theavailable data and its deconfliction of military and commercial radar tracks in the vicinity of thesighting. The partner assesses with high confidence that the object was not anomalous and very
likely was some kind of balloon.
• (U) The S&T partner assesses that the image is consistent with a Mylar balloon as viewed
from above where the bottom is illuminated with light reflected from the clouds or theearth. This effect is known as “Earth shine.”• (U) The partner notes that many larger balloons have red-colored tether points around thecircumference of the balloon which could account for the orange-red color the pilot
reported observing near the center.

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UNCLASSIFIEDUNCLASSIFIED(U) Figure 1: Comparison of reported UAP (A: Infrared image of reported object, B: Electro-optical imageof reported object, and C: Image of a commercial LTA lighting system) (Photo credit: AARO)

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UNCLASSIFIEDUNCLASSIFIED(U) Figure 2: Pilot’s drawing of the reported object

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UNCLASSIFIEDUNCLASSIFIED(U) Figure 3: The below is a visualization of the pilot’s point of view of the object based on the position
and altitudes of the aircraft and object, the look angle of the sensor, and the sun geometry

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