What is Contrail?
[[File:Boeing 747-436, British Airways, over Pecna (Poland) 15.02.11 (5446601614).jpg|thumbnail|A [[Boeing 747]] leaving a contrail.]] A '''contrail''' ([[condensation]] trail) is a cloud-like trail of [[water vapor]] or ice crystals left by an [[airplane]]. When jet [[fuel]] burns, it produces water vapor and [[carbon dioxide]]. The water vapor condenses (turns from gas to [[liquid]]) because of the low temperature at the high [[altitude]] that the plane is flying. The [[chemtrail]] conspiracy theory claims that these trails may contain harmful chemicals being sprayed by government organizations. [[Category:Aviation]] {{science-stub}}