what are the smoke lines those planes leave?

Question

have you ever seen those jets or planes..whatever they are that pass trhough the sky leaving a long line of smoke....what is the purpose of those planes..

Answer 1

They are called contrails. when moist air is disturbed it forms a cloud. what you're seeing is a trail of cloud behind the plane. Because the air is not moist enough to form clouds by itself, after the disturbance settles down, it evaporates and disapears.

Answer 2

Planes only release smoke deliberately during flight demonstrations such as airshows. Normal operation of engines at high altitudes produce a vapor trail caused by hot engine exhaust condensing in the thin, cold atmosphere of high altitudes.

Answer 3

There's two. One is actually smoke. This is actually done for a fee for people on the ground for particular reason than to see it done. If it's a jet, that is not smoke. It is called a contrail. Or, a moisture condensation trail which sloooooowwwwllly evaporates on account of it's so nippy up there.

Answer 4

that's not smoke but because the air is saturated and can't absorb any more water, and there is water vapor produced when the fuel is burnt so the water vapor from the exhaust will appear as white lines. this is called Contrail. it can also be caused by wing tip vortices.

Answer 5

They're called contrails, when the environment is just right, they leave the trails you see in the sky.

Answer 6

They are the emissions that the airplanes leave behind!!! And the purpose of the planes' emissions are zero positive.

Answer 7

hot exhaust mixes with cold atmosphere and creates water vapors

Answer 8

It is the heat of their engines that appears in the cold air.

Answer 9

It is water vapor.