what is in the chemtrails?

Answer 1

Chemtrails are just a "conspiracy theory". They're really just standard contrails of a plane that some people think are laced with dangerous chemical/bilogical agents, but nothing has proved this theory correct. Search around on the internet, you'll see some really good articles about it from both sides of the argument. Anyway, to partially answer your question, contrails are trails of condensation and artificial cirrus clouds made by the exhaust of aircraft engines/wingtip vortices which precipitate a stream of tiny ice crystals in moist, frigid upper air.

Answer 2

Isqueiro resumes it very well. There is nothing to add, other than to give him a thumb-up.
If you want more colourful explanations of chemtrails, try another category such as Alternative science but not Weather. Here, we are the boring bunch; only interested by facts! :-)