WONDER #265: Why Do Airplanes Leave Tracks in the Sky?

Question 1 of 3

The word “contrail” comes from what phrase?

1. cloud rail
2. condensation trail
3. constant rail
4. airplane condensation

Question 2 of 3

The artificial cloud you see behind an airplane is actually a mixture of what?

1. smoke from the plane\'s engine and water vapor
2. condensed water vapor and ice crystals
3. cold air and gasoline
4. hot air and oil

Question 3 of 3

When did pilots first start writing messages in the sky with their airplanes?

1. as early as 1915
2. after World War II
3. in the 1960s
4. within the past 10 years

Check your answers online at https://wonderopolis.org/wonder/why-do-airplanes-leave-tracks-in-the-sky.