What Causes the Smoke Trails Behind Airline Planes High in the Sky?

Mike L. asks: What is the chemtrail smoke behind airliners? So called “chemtrails,” though more technically known as contrails, first appeared behind planes going all the way back to the earliest days of high altitude flight. One of the earliest known surviving references of such occurred when an American soldier by the name of Captain Ward Wells observed a peculiar … Continue reading What Causes the Smoke Trails Behind Airline Planes High in the Sky?