AARO Aguadilla Resolution Report, March 2025

Brief

On April 26, 2013, a CBP infrared sensor aboard a De Havilland Canada 8 aircraft near Aguadilla, Puerto Rico recorded two objects moving at approximately 8 mph, closely matching the recorded wind speed of 9.8 mph. AARO's Systems Toolkit reconstruction confirms the objects remained over land throughout; the apparent disappearance into the Atlantic Ocean is explained by thermal crossover reducing IR contrast against the ocean background. Apparent high speed is attributed to motion parallax, and the 'splitting' behavior to a camera angle shift from side-on to top-down as the aircraft gained altitude. AARO attributes the objects with moderate confidence to sky lanterns, supported by pixel-estimated size under one meter, flickering thermal signatures consistent with fuel burn-off, and vendor confirmation that area hotels routinely release sky lanterns during celebrations.

Metadata

Agency

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

Release

2025-03-20

Type

PDF • .pdf

Length

7 pages

Classification

UNCLASSIFIED

Programs

Systems Toolkit (STK), Minimum Separation Vectors

Tags

sky lanterns, infrared sensor, Puerto Rico, 2013, transmedium claim debunked, motion parallax, thermal crossover, Aguadilla, CBP aircraft

Key points

• STK reconstruction placed objects at approximately 656 feet altitude, moving at 8 mph in a straight line consistent with recorded wind speed of 9.8 mph from the east/northeast.p.3
• Apparent high speed was caused by motion parallax, the aircraft's own flight speed, sensor zoom, and changing relative positions made slow-drifting objects appear to move at extreme velocity.p.3
• AARO assesses with high confidence the video depicts two distinct objects throughout; they visibly separate at 00:29.56, 00:40.76, and 00:47.00 seconds within the first minute alone.p.3
• Objects remained over land during the entire encounter; apparent entry into the Atlantic Ocean was thermal crossover, the objects' IR signatures became indistinguishable from the ocean background rather than submerging.p.5
• Pixel analysis estimated both objects at under one meter (three feet) in diameter with indistinct shapes, consistent with sky lantern dimensions.p.5
• AARO confirmed with local hospitality industry vendors that releasing sky lanterns during celebrations is common practice for hotels and resorts in the Aguadilla area.p.5
• Thermal crossover conditions were active at time of recording: sunset was at 7:48 p.m. local time and the IR sensor recorded at 9:22 p.m., within the two-hour window when thermal crossover can influence IR sensor return.p.6
• AARO rejected three competing explanations, anomalous phenomena (ruled out by pixel analysis and STK), marine birds (inconsistent with straight-line wind-speed travel and absence of wing features in IR), and mylar balloons (IR sensors cannot detect reflected moonlight).p.7

Verbatim

• AARO assesses with high confidence 1 that the objects did not exhibit anomalous behavior or transmedium capabilities. AARO assesses with moderate confidence that the objects were a pair of sky lanterns.

  p.1

• The objects appeared to move at a high rate of speed over the airport and surrounding area before separating from one another.

  p.1

• Motion parallax is an optical effect that induces an observer to perceive that a stationary or slow-moving object is moving much faster than its actual speed when viewed from a moving frame of reference.

  p.3

• The objects visibly separate multiple times within the first minute, suggesting that the video depicts two objects the entire time.

  p.3

• AARO confirmed with local hospitality industry vendors that it is common practice for hotels and resorts in the area to release sky lanterns during celebrations.

  p.5

• Sky lanterns are typically smaller than one meter in diameter and emit a flickering, weakening thermal signature as they expend fuel, gradually losing distinctiveness against the background environment when viewed through an IR sensor.

  p.5

• On April 26, 2013, sunset occurred at 7:48 p.m. local time. The IR sensor recorded the event at 9:22 p.m. local time, within the two-hour window when thermal crossover can influence IR sensor return.

  p.6

Most interesting

• The range between the aircraft and the objects nearly tripled during the encounter, degrading IR sensor fidelity and making slow, small objects progressively harder to characterize.
• An AARO partner had independently assessed the objects as marine birds traveling 35 to 130 mph at 300 to 900 feet, a speed range AARO's STK reconstruction directly contradicts.
• A separate partner attributed the fluctuating IR return to moonlight reflected off mylar balloons; AARO rejected this on the technical grounds that IR sensors do not detect reflected moonlight.
• The aircraft gained approximately 1,725 feet in altitude during the encounter, shifting the sensor view from side-on to top-down, the geometric change, not any object behavior, made the 'splitting' appear more dramatic near the end of the video.
• Pixel analysis was used to rule out the hypothesis that the objects passed behind a utility pole, which would have implied both much lower altitude and much higher speed than AARO assessed.