Black Triangle

Black triangles are the silent, slow-moving, triangular or boomerang-shaped platforms, typically described with distinct lights at each corner, reported in mass sighting waves from the 1980s onward — the Hudson Valley boomerang wave beginning in 1982, the intense Belgian wave of 1989-92 tracked partly by NATO-liaised military radar, the 1997 Phoenix Lights, and the Illinois triangle sightings of 2000. The shape's rise to prominence tracks closely with the psychosocial hypothesis's broader "shape drift" argument: black triangles became ufology's dominant reported form during exactly the decades when stealth aircraft, angular radar-evading design, and classified black-budget programs were most prominent in public awareness, mirroring the era's defining aviation technology the same way discs mirrored 1947's saucer coinage. Proposed explanations span the full range of the debate: classified military aircraft (the rumored TR-3B foremost among them), conventional civilian or military aircraft flying in tight formation and misperceived as a single solid object (a pattern related to "contour illusion"), or, for researchers who take the reports at face value, something genuinely unidentified. The Belgian wave remains the best-instrumented black-triangle case on record, since Belgian air force F-16s were scrambled on radar-guided intercepts against the reported objects on more than one occasion during the flap.