AARO Eglin AFB Case Resolution, October 2023

Brief

On January 26, 2023, a military pilot detected four objects on radar between 16,000 and 18,000 feet in the Eglin AFB training range; only one was ever visually confirmed and photographed via EO/IR sensor. AARO, supported by independent IC and S&T partners, concluded at moderate confidence that the object, gray, paneled, roughly 12 feet in diameter with orange-red center coloring, matched the physical characteristics of a large commercial helium-filled lighting balloon, a finding reinforced by laboratory testing on a comparable unit. The radar malfunction that occurred when the pilot closed to 4,000 feet was attributed to a pre-existing circuit-breaker fault that had tripped three times on the same aircraft in prior months. Both the IC and S&T partners independently assessed at high confidence that the object exhibited no anomalous characteristics.

Metadata

Agency

All-domain Anomaly Resolution Office (AARO), U.S. Department of Defense

Release

2023-10-14

Type

PDF • .pdf

Length

7 pages

Classification

UNCLASSIFIED

Tags

LTA balloon, EO/IR, radar, Florida, Eglin AFB, 2023, formation, commercial lighting balloon, infrared contrast

Key points

• Four objects were initially detected on radar between 16,000 and 18,000 feet in apparent formation; only one was ever visually confirmed or imaged by the pilot.p.1
• The aircraft's video recording equipment was inoperable before and during the flight, leaving only two EO/IR still images as the entire visual evidentiary record.p.1
• The pilot reported the object was approximately 12 feet in diameter, gray with a paneled surface and orange-red coloring at the center, and either moved very slowly or was potentially stationary.p.1
• In a post-flight discussion with AARO, the pilot added a description of a vertically oriented engine nearly the height of the object, a detail absent from the initial report and not visible in either EO/IR image.p.2
• Radar failed when the pilot closed to 4,000 feet; the same circuit breaker had tripped three times on the same aircraft in prior months, leading AARO to assess the malfunction was coincidental and pre-existing.p.2
• AARO conducted laboratory testing on a commercial lighting balloon with similar physical characteristics and found it could replicate aspects of the pilot's account, including the paneled surface appearance and infrared hemisphere contrast.p.3
• The IC partner reconstructed event geometry, altitude, geocoordinates, sensor viewing angle, aircraft heading, and sun geometry, and assessed at high confidence that sun illumination of the lower hemisphere was fully consistent with the infrared image.p.4
• The S&T partner introduced the 'Earth shine' effect (light reflected from clouds or ground) to explain the infrared lower-hemisphere brightness, and noted red-colored tether points common on large balloons could account for the orange-red color.p.4
• Both the IC and S&T partners independently reached high-confidence assessments that the object did not exhibit anomalous characteristics and very likely was some form of balloon.p.3

Verbatim

• The pilot described the object as gray with a paneled surface and orange-red coloring at the center.

  p.1

• The pilot visually perceived a heat signature emanating from the rounded bottom portion, which they described as "blurry air."

  p.2

• The pilot reported that upon closing to within 4,000 feet of the object, the radar on the aircraft malfunctioned and remained disabled for the remainder of the training exercise.

  p.2

• AARO assesses the reported UAP very likely was an ordinary object and was not exhibiting anomalous or exceptional characteristics or flight behaviors.

  p.2

• The "blurry air" observation could have been a visual misperception due to environmental conditions and potentially resulted from a tether hanging below the LTA object or motion-induced image blurring.

  p.3

• 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 the earth. This effect is known as "Earth shine."

  p.4

• The partner notes that many larger balloons have red-colored tether points around the circumference of the balloon which could account for the orange-red color the pilot reported observing near the center.

  p.4

Most interesting

• Three of the four radar-detected objects were never visually confirmed, leaving their nature entirely unresolved within this case file.
• The pilot's account expanded materially between the initial report and the follow-up discussion with AARO, the 'vertically oriented engine' description was added post-flight and is invisible in both EO/IR images.
• AARO physically procured and tested a comparable commercial lighting balloon in a laboratory setting, finding that the seams of its fabric panels could be perceived as the 'paneling' the pilot described.
• Commercial lighting balloons can be converted from corded AC power to battery power, making untethered flight operationally plausible, a finding AARO confirmed during lab testing.
• The upper black hemisphere of commercial lighting balloons is lined with reflective material to direct light downward; this structural feature produces precisely the strong infrared contrast seen in the EO/IR image.
• Sun angle geometry, reconstructed independently by the IC partner, placed direct illumination on the lower hemisphere of the object at the exact moment of observation, providing a physics-grounded explanation for every anomalous-seeming feature in the image.