What is that white line behind jets way up in the sky?

Question

Is it some sort of marker they secrete?

Answer 1

Jet fuel is a hydrocarbon. When it's burned, the "hydro-" part of it, hydrogen, combines with oxygen to form water. When the water vapor hits the below-zero air up there, it condenses into water liquid droplets -- just like what clouds are made of. This condensation trail -- called a "contrail" for short -- is that white line: a long thin artificial cloud.

Only skywriting planes deliberately make lines in the sky. (I don't know what markers they use.)

Answer 2

For the best answers, search on this site https://shorturl.im/awyMi

Contrails - which are ice crystals. Jet fuel is a kerosene based fuel, and often contains suspended water droplets... When the fuel is burnt at high altitude, the gases from the exhaust of the jet carry these water particles (which are obviously unburnt) into the atmosphere behind the aircraft where they promptly freeze due to the extremely cold outside air temperature - and form the contrails we see as a white line! Hope this helps :-)

Answer 3

Contrails, the condensation trail emitted by jet aircraft exhaust are called contrails. Contrails form when hot humid air from jet exhaust mixes with environmental air of low vapor pressure and low temperature

Answer 4

A jet sucks in very cold air from that altitude. The jet engine heats the air up over and over causing it to expand, which creates propulsion. During the heating process, there is condensation (vapor) and that is expelled out the back of the jet engine. Just like when you go outside on a cold morning and you can "see your breath: - basically it's the same thing. Warm, moist air being propelled into cold air. I hope that helps.

Answer 5

It's called a contrail, and is basically jet engine exhaust. It is not an intentional marker.

Answer 6

contrails, water vapour from the engines.

Answer 7

Well dear, it's water vapour - that's why it is called a vapour trail.