Black triangle (UFO)
Regarding the triangular shapes, the report also states: "Occasionally ... it seems that a field with, as yet, undetermined characteristics, can exist between certain charged buoyant objects in loose formation, such that, depending on the viewing aspect, the intervening space between them forms an area (viewed as a shape, often triangular) from which the reflection of light does not occur.
"[5] A recommendation in the report is that no attempt be made on the part of aircraft to intercept or outmaneuver these objects, and instead to place them astern to mitigate the risk of collision.
[6] The report also speculates that the hypothesized plasma formations, through their "magnetic, electric or electromagnetic" fields, could have the potential to induce in observers vivid, but mainly incorrect, perceptions.
Several pilots claimed responsibility for these UFOs, reporting that the objects, some tracked to a local airport and parking lot, were ultralight aircraft flown in formation.
Some residents reported one of the black triangles to be over a mile wide and that it drifted slowly over their houses, blocking out the night sky's stars.
[13] The incident was featured in several television shows including Seeing is Believing, a Discovery Channel special UFOs Over Illinois, and an episode of the Syfy series Proof Positive.
[19][20] In the 2023 Netflix documentary series Encounters, it is claimed that there were black triangles and inside were what looked like insects or a praying mantis.
A geographic analysis by the now-inactive National Institute for Discovery Science suggested that black triangles might be U.S. Air Force craft.
[22][23] Geoscientist Ben McGee has identified border patrol drones with infrared anti-collision or identification lights to explain some black triangles.
