AARO Website Launch: Eglin Resolution

Brief

On 26 January 2023, a military pilot over the Eglin AFB training range off Florida's coast tracked four objects on radar between 16,000 and 18,000 feet appearing to fly in formation; video recording equipment was inoperable, leaving only two EO/IR still images of one object as sensor evidence. AARO, an Intelligence Community partner, and a Science & Technology partner each independently assessed the imaged object as non-anomalous, most likely a large lighter-than-air object such as a commercial helium lighting balloon. A radar malfunction that occurred when the pilot closed to 4,000 feet was judged coincidental, linked to a circuit breaker that had tripped three times previously on the same aircraft. AARO's confidence in the balloon identification is moderate, constrained by the limited available data.

Metadata

Agency

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

Release

2023-08-31

Type

PDF • .pdf

Length

7 pages

Classification

UNCLASSIFIED

Programs

AARO

Tags

lighter-than-air balloon, EO/IR, radar, Eglin AFB, Florida, 2023, rounded cone shape, commercial lighting balloon

Key points

• Pilot tracked four objects on radar at 16,000–18,000 feet appearing to fly in formation; only one was visually observed and photographed.p.1
• Aircraft video recording equipment was inoperable before and during the flight, leaving only two EO/IR still frames as sensor evidence for the analyzed object.p.1
• Pilot described the object as approximately 12 feet in diameter, gray with a paneled surface, orange-red at center, and shaped like an Apollo spacecraft, rounded bottom and rounded three-dimensional cone top.p.1
• Pilot reported a perceived vertically oriented engine affixed to the side of the object; this feature is absent from both EO/IR images, was absent from the initial report, and AARO had no data to corroborate it.p.2
• Radar malfunctioned when the pilot closed to within 4,000 feet; post-mission review found a tripped circuit breaker that had tripped three times previously on the same aircraft without a diagnosed root cause.p.2
• AARO laboratory-tested a commercial helium lighting balloon and found its fabric-panel seams could be perceived as 'paneling,' and confirmed these balloons can be converted to battery power for untethered operation.p.3
• AARO's IC partner and S&T partner independently reached high confidence assessments that the object was not anomalous and very likely was some form of balloon.p.3
• S&T partner attributed the orange-red coloring to red-colored tether points common on large balloons, and the luminance differential to an 'Earth shine' effect from light reflected off clouds or the ground.p.4

Verbatim

• A military pilot reported the object due to its potential as a flight safety hazard and an incursion into a sensitive training range

  p.1

• the pilot reported the object was about 12 feet in diameter and that it either moved very slowly or was potentially stationary

  p.1

• 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 submitted the case for review to an Intelligence Community (IC) component and a science and technology (S&T) partner; these two partners independently reached high confidence assessments that the object did not exhibit anomalous characteristics or behaviors and, therefore, was an ordinary object.

  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

Most interesting

• AARO physically acquired and laboratory-tested a commercial helium lighting balloon, confirming it could replicate multiple features of the pilot's account including hemispheric infrared contrast and perceived paneling.
• The three other objects observed on radar were never visually acquired or photographed; AARO had no EO/IR data for them and could not analyze them at all.
• The pilot's claim of a visible engine affixed to the object's side appeared only in the post-incident discussion with AARO, it was not in the initial report and is invisible in both sensor images, raising standard reliability concerns about delayed recollection.
• Commercial lighting balloons designed for outdoor events and construction sites can be converted from corded AC power to battery power, meaning one could plausibly operate untethered and aloft.
• The S&T partner's work included deconflicting military and commercial radar tracks in the vicinity, a cross-domain data step that goes beyond simple image analysis.
• Sun geometry was modeled precisely by both the IC and S&T partners to show that the sun's angle at the time and place of the sighting would illuminate the balloon's bottom hemisphere in a pattern matching the EO/IR image, eliminating the need to invoke anomalous light emission.