WONDER #265: Why Do Airplanes Leave Tracks in the Sky?
Question 1 of 3
The word “contrail” comes from what phrase?
- cloud rail
- condensation trail
- constant rail
- airplane condensation
Question 2 of 3
The artificial cloud you see behind an airplane is actually a mixture of what?
- smoke from the plane\'s engine and water vapor
- condensed water vapor and ice crystals
- cold air and gasoline
- hot air and oil
Question 3 of 3
When did pilots first start writing messages in the sky with their airplanes?
- as early as 1915
- after World War II
- in the 1960s
- within the past 10 years
Check your answers online at https://wonderopolis.org/index.php/wonder/why-do-airplanes-leave-tracks-in-the-sky.