A chemtrail is a trail of chemicals left by an airplane at a high altitude. According to a conspiracy theory, the chemicals are said to be deliberately sprayed for reasons that are kept secret by the government.[1] Most scientists and workers in the aviation industry say that the trails left by planes are just a form of condensation. These are called contrails, or condensation trails.[2][3]
↑Watson, Traci (7 March 2001). "Conspiracy theories find menace in contrails". USA Today. Archived from the original on 30 August 2011. Retrieved 1 October 2011. The theory: The white lines of condensed water vapor that jets leave in the sky, called contrails, are a toxic substance the government deliberately sprays on an unsuspecting populace.