Northbrook, Cook County, Illinois, May 27, 2006, 9:12 PM — A former pilot observes six large dull-white disc-shaped objects in a precise 3-2-1 inverted-triangle formation under solid overcast. Objects appeared sequentially, held formation, and vanished over approximately 35 seconds.
THINK ABOUTIT UFO|UAP SIGHTING REPORT
2006: Disc Sighting in Northbrook, Illinois
On the evening of May 27, 2006, a former pilot in Northbrook, Illinois, stepped outside to walk his dog and looked up into a gray, starless overcast — and watched six large white discs, each estimated at 100 feet or more in diameter, materialize in a precise inverted-triangle formation before vanishing and partially reappearing over approximately thirty-five seconds. The witness was emphatic on one point: these were not lights. They were dull white, translucent objects with a constant glow evenly distributed across their surfaces, maintaining perfectly equal spacing in a 3-2-1 “Christmas tree” configuration. The discs did not pulse, did not drift, and did not deviate from formation. They appeared sequentially — first three, then two in front, then a single lead disc — held position for approximately eight seconds per phase, then vanished and briefly reappeared as two before disappearing permanently. The witness, a self-identified former pilot, stated he had extensive experience identifying aerial phenomena under varying weather conditions, and was certain these were solid objects, not illumination artifacts.
Date: May 27, 2006
Sighting Time: 9:12 PM
Day/Night: Night (dusk/evening, overcast)
Location: Northbrook, Cook County, Illinois
Urban or Rural: Suburban
No. of Entity(‘s): None observed
Entity Type: N/A
Entity Description: N/A
Hynek Classification: DD (Daylight Disc) — although observed at dusk under overcast, the witness explicitly states these were solid objects with surface area and constant glow, not point-source lights. DD is more appropriate than NL.
Duration: Approximately 35 seconds total
No. of Object(s): 6 (appearing in sequential groups of 3, then 2, then 1)
Description of Object(s): Six large disc-shaped objects, dull white and translucent with a constant glow evenly distributed across their surfaces. Not pulsing, not point-source lights. Arranged in a perfect inverted triangle (3-2-1 “Christmas tree” configuration) with equal spacing between all objects both laterally and in depth. Appeared sequentially: first three, then two additional in front at identical spacing, then one leading disc. Held formation approximately 8 seconds per phase.
Shape of Object(s): Disc
Size of Object(s): Estimated at least 100 feet or more per disc
Color of Object(s): Dull white, translucent
Distance to Object(s): Not specified — observed to the northwest, altitude indeterminate under solid overcast
Height & Speed: Stationary — no lateral movement observed; objects appeared and vanished in place
Number of Witnesses: 1
Special Features/Characteristics: Sequential appearance in precise formation (3-2-1 inverted triangle); perfectly equal spacing maintained; objects appeared as solid surfaces with distributed glow rather than point-source lights; witness is a self-identified former pilot with aerial observation experience; objects vanished and partially reappeared (two discs) before final disappearance; witness drawing included with the report
Source: UFOEvidence.org (report ID 9348)
Case Status: Insufficient Data
Summary/Description: On May 27, 2006, at 9:12 PM, a former pilot in Northbrook, Cook County, Illinois, observed six large dull-white translucent disc-shaped objects arranged in a precise inverted-triangle (3-2-1) formation to the northwest under solid overcast. The objects appeared sequentially in groups, held formation for approximately 8 seconds per phase, then vanished. The witness emphasized these were solid objects with evenly distributed surface glow, not lights. Total duration approximately 35 seconds. Single witness, no corroboration.
Related Cases: O’Hare Airport Disc (November 7, 2006) — same metropolitan area, same year
Detailed Report
The Northbrook disc formation sighting of May 27, 2006, is a brief but technically interesting observation reported by a witness who identified himself as a former pilot with experience evaluating aerial phenomena under varying weather conditions. The report was submitted to UFOEvidence.org with an accompanying witness drawing.
At exactly 9:12 PM on Saturday, May 27, 2006, the witness walked out of his home in Northbrook, Illinois, to walk his dog. The sky was a uniform dark gray overcast with temperatures in the 70s and possible rain approaching. No stars were visible. Looking up to assess the weather, the witness noticed three large disc-shaped objects positioned to the northwest. The objects were white and translucent, arranged in perfect alignment. He observed them for approximately eight seconds before two additional discs of identical size appeared in front of the first three, spaced at the same distance as the lateral separation between the original discs. This second row appeared for approximately eight seconds before a sixth disc appeared in front of the pair, completing a perfect inverted triangle or “Christmas tree” formation — six objects arranged 3-2-1 with uniform spacing in all directions.
The complete formation held for approximately eight more seconds, then all six objects vanished. After approximately eight seconds of absence, the two middle-row discs reappeared briefly — again for roughly eight seconds — before vanishing permanently. The witness remained outside for fifteen to twenty additional minutes observing the sky but saw nothing further.
The witness was emphatic about several observational details that he considered definitive. The objects were not lights: they had visible surface area with a constant, non-pulsing white glow evenly distributed across the disc surface. They were dull rather than brilliant. As a former pilot, the witness stated he had extensive familiarity with how lights appear in the sky under different weather conditions, and these objects did not resemble any known aerial light source. The discs were estimated at 100 feet or more in diameter. The formation geometry was mathematically precise — all lateral and depth spacings were identical.
Researcher’s Notes
The Northbrook Formation — Illinois 2006 and the Sequential-Appearance Problem
- Classification Correction: The existing page listed NL (Nocturnal Light). This is incorrect. The witness explicitly states “they definitely were not lights” and describes objects with visible surface area and evenly distributed glow — characteristics of solid objects, not point sources. The correct classification is DD (Daylight Disc), applied to metallic or solid objects observed under ambient light conditions. While the observation occurred after sunset under overcast, the objects themselves were self-luminous with discernible disc geometry. DD more accurately captures the observation than NL.
- Source Chain Assessment: Single anonymous witness report submitted to UFOEvidence.org, a now-defunct online UFO reporting database. No investigation was conducted. No MUFON or NUFORC case number is associated with the report. The witness’s claim of pilot experience cannot be verified. A witness drawing was submitted. This is an unverified self-report with no corroboration.
- Sequential Appearance Pattern: The most analytically interesting feature is the sequential materialization pattern — three objects appearing first, then two, then one, in precise formation spacing. This sequential-build pattern is reported occasionally in the UFO literature and resists conventional explanation. Flares, sky lanterns, and conventional aircraft formations do not materialize sequentially in place without lateral movement. The pattern is consistent with either a display behavior (objects becoming visible in sequence) or a large single object with illumination zones activating sequentially. The uniform eight-second timing across all phases is suggestive of programmatic rather than random behavior.
- Geographic Context: Northbrook is a northern suburb of Chicago in Cook County. The May 2006 observation predates the famous O’Hare Airport disc sighting by approximately six months. While the two events differ significantly in witness quality and investigative depth, both involve disc-shaped objects observed in the greater Chicago metropolitan area in 2006. No causal connection should be inferred from temporal and geographic proximity alone.
The Northbrook formation sighting rests on a single unverified witness report with no investigation, placing it firmly in Insufficient Data. The witness’s self-identified pilot credentials, if genuine, would add observational credibility, but cannot be confirmed from the available record. The sequential-appearance pattern and the witness’s emphatic distinction between lights and solid objects are noted as details that elevate the report above routine NL submissions, but do not substitute for corroboration.
Media
Witness’ drawing of the sighting.
