Case file No. 11 · Secrets and hoaxes
Long trails behind aircraft are not condensation but chemicals secretly sprayed on the population, to control weather, health or minds.
The trails are condensation. No spraying program has been found.
Trails form and persist depending on temperature and humidity at altitude. Atmospheric scientists surveyed in a study found no evidence of a secret spraying program. The claims that rely on tests of water or soil do not show spraying.
Contrails are clouds of ice crystals that form when hot, humid exhaust from jet engines meets very cold air. The conditions in which they form were worked out in 1953 [2]. Whether a trail disappears quickly or spreads out into a lasting cloud depends on how humid the air at that altitude is [3]. In a 2016 survey, 76 of 77 atmospheric scientists and geochemists said they had seen no evidence of a secret spraying program, and the one who answered differently pointed to unusual barium levels in a single sample with other possible causes [1]. Weather modification, such as cloud seeding, exists but is small and public [4].
Claims that supporters often repeat and that we looked for but could not confirm in a reliable source.
Hot exhaust from jet engines contains water vapour. At high altitudes, where the air is very cold, the vapour freezes into ice crystals, producing a visible trail. The conditions for this were described in 1953 [2]. If the surrounding air is dry, the crystals evaporate quickly. If it is humid, the trail persists and can spread into cirrus-like cloud [3].
In a 2016 survey of 77 atmospheric scientists and geochemists, 76 reported that they had seen no evidence of a secret large-scale spraying program, and the other cited a single sample with barium levels that has other possible explanations [1].
Soil and dust naturally contain aluminium and barium. A test result of these metals does not tell where they came from. To show spraying you would need to link a substance to aircraft, and no such link has been shown [1].
Spraying the whole sky would involve many thousands of flights, tonnes of materials, and pilots, mechanics and suppliers. After decades, no insider, document or receipt has emerged [1].
Contrail cirrus has a real effect on climate, and its size is an active subject of research, including whether changing flight routes could reduce it [3].
If you are worried about air quality, local monitoring stations publish measurements of particles and metals. Compare them with reference values. The reading of one sample is not enough [1].
15 November 2026: First publication. Verdict: Explained.