Con-Trails or vapour trails are condensation trails made by the exhaust of aircraft engines or wingtip vortices which precipitate a stream of tiny ice crystals in moist, frigid upper air. Being composed of water, the visible white streams are not, in and of themselves, air pollution. However, contrails generated by engine exhaust are inevitably linked with typical fuel combustion pollutants. Contrails might also be considered visual pollution.
Note the short white line. It disappears because it’s made of water.
This powder-like substance will linger in the air for hours before settling on your lawn.
Chem-Trails are a chemical and/or biological agent of some sort that is being released. The term “chemtrail” does not refer to common forms of aerial dumping (e.g. crop dusting,cloud seeding or aerial firefighting).
It specifically refers to systematic, high-altitude dumping of unknown substances for undisclosed purposes, resulting in the appearance of these unusual contrails.