This is an interesting photo from NASA Langley Research Center. It shows condensation trails (contrails for short) over the southeastern United States. These line shaped clouds form from the condensation of water vapor in the exhaust of high flying jet aircraft. Temperatures are extremely cold at the cruising altitudes of commercial aircraft so the contrails are made primarily of ice crystals.
I’d rather have questions that cannot be answered than answers that cannot be questioned.
— Richard Feynman, PhD
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