Why do planes leave trails

B Jun 19, I have never seen it be done before but it looks pretty. The work they do is awesome. Teiona M. Jun 19, I liked that you guys told us about why air planes leave trails. Also how they leave letters with the air planes. Monet Gray Jun 19, I liked how you can write words in the sky with the planes. I also like when you make shapes that's really pretty. Once i went to a air show and it had people sky writing and it was really cool. I would love if someone did that to me.

That sounds like a lot of fun, Monet Gray! We bet you learned a lot! Anya A. Thats cool how people can purpose by skywriting. I didnt know that skywritting was way back to I saw a air show before its really cool. Cole H Jun 19, I didnt know that the "special smoke" was made from the exhaust overheating and oil being sprayed on it. Pretty odd. Jun 21, S May 6, Funny because when I was younger and saw sky writing or airplane trails I always used to think that they were a special thing only for me and no one else.

I don't know why that is just how my brain used to work, now reading this I am very interested!!! Wonderopolis May 6, Ilma May 6, I never knew that airplane engine produces exhaust, just like the car do. I also didn't know that pilots have to learn different patterns and work on the smoking machines, and be able to write unique messages in the sky.

It is also way different, how the skywriters use to do things in olden days than comparing to today. Hung May 6, I never knew most of those facts until today. That was what i had to do for my homework. So I liked it. Great, Hung! I do believe the lines in the skies create magical sunsets and direct us to spiritual awakenings. Wonderopolis Apr 20, Earnest Hemingway Apr 1, Wonderopolis Apr 1, Ryan Jan 23, Let me begin by informing you that I work in the Aerospace Industry as an engineer.

Your article has some useful information. You are buying into the narrative. I'm not arguing that planes exhaust water vapor as a result of combustion, nor am I arguing that the water condensation will dissipate and fade away.

There is science behind what you are saying, but I want you to do something. Look at our sky. Next time you are walking around the yard or into wal-mart or whatever and you see the plane actually leaving the so called "condensation trails", look around.

It is almost guaranteed that you will not only see one. These planes are spraying whatever they are spraying in a strategical pattern. Return to that same spot each hour over the course of hours. These trails do not dissipate. These trails do not fade until many many hours after they should have. We have always just accepted this as "overcast" conditions. We have always just accepted the water vapor emission and condensation is what is being emitted from these planes.

We as society do not pay attention anymore. And our government has definitely capitalized on this fact. It was only recently that someone told me to do exactly what I am telling you and I now see it.

With my own eyes. Best of luck, Cheers! Wonderopolis Jan 23, Ryan Jan 26, Wonderopolis Jan 26, Makani Jun 22, Debbie Dec 23, There are pictures all over the Internet of these trails that look like they have started and stopped. This is because the pilots have the ability to turn this aerosol on and off. Wonderopolis Dec 29, Hi Debbie! Thanks for sharing your comment with us. Joe Dec 23, How does this tie in to Solar Radiation Management? My friends told me that they spray aluminum particles into the air in order to reduce global warming.

How can you tell the difference in the normal contrails and the aluminum contrails? Wonderopolis Dec 23, Amy Dec 23, Those "exhaust trails" as you call it are nothing more the a toxic chemical concoction that they are spraying out to manufacture weather. In commercial flights, it's a mix they've developed for jet fuel. Also, military often sends planes and drones to do mass spraying.

The spray contains toxic reflective metals such as barium, lithium, strontium, boron, and much more. Which is why people are starting to see such strange colors at sunrise and sunset and some clouds during the day that appear pink, yellow, blue, and green. The also spray nano tech such as smart dust. Mohit Dagar Dec 6, But some time we seen two same that type of airplane in the sky but one airplane leave track for few minute and another airplane leave for more time?

Wonderopolis Dec 8, Jan Nov 4, Here's the thing, I am over 70 years old and I love a blue, blue sky or large beautiful clouds and have always gazed at the sky everytime I am outside almost always. These so called chemtrails are something new and I do not think it's normal procedure for a jet to fly back and forth or several planes until the sky is covered with these trails Whatever it is, you can bet it's not normal.

Wonderopolis Nov 4, Jeremy Mayer Oct 6, Oct 8, Laney Mar 21, If that is true, why don't I have to drive back through my exhaust a few hours later if I am returning from where I just drove, or see auto exhaust fumes that linger all day long next to roadways? Planes leaves these contrails in the skies all day sometimes and change the sky to a nasty white haze.

It just doesn't add up to harmless water vapor. More like geoengineering. No matter how you look at it, there is too much of this going on in our atmosphere, and that cannot be great for the environment, or the air we breathe, because what goes up, must also fall down. Wonderopolis Mar 21, JJ Dec 11, Dec 12, Thank you for sharing your experience, JJ.

We are glad you visited Wonderopolis. Wonderopolis Nov 26, We think you're cool, Sydney! Maybe it's communication involved by the military. Unger science class EH Nov 22, It's cool how planes leave lines behind them. How does that happen? Thank you. Wonderopolis Nov 22, Cindy Nov 18, Wonderopolis Nov 18, Have you ever noticed the airplane tracks before?

Renux Apr 15, Tera's right When the contrails are visible and strong, it is possible to see the white streaks become wavy and then leave rings floating high in the sky, like smoke rings from a giant cigar.

Recent research has suggested that the ice clouds contained in contrails cause greenhouse effects and contribute to global warming as part of the insulating blanket of moisture and gases in the atmosphere. Researchers in this area seized on the opportunity presented on September 11 and 12 over the U. The complete cessation of commercial air traffic offered a control sky without contrails for use in quantifying the environmental effects of contrails.

Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. Get smart. Contrails are extremely similar in composition, though differ greatly in their life span.

The weather directly influences how long a contrail exists for. Contrails are generally classified in three distinctions: short-lived, persistent non-spreading , and persistent spreading. Short-lived contrails resemble short white lines which tail the plane. As their name suggests, the trails only last a few minutes before they disappear nearly as fast as they are made. The air which the plane travels through is somewhat moist with only a small amount of water vapor available.

Any ice particles created quickly return back to a vapor state. Source: NASA. Persistent non-spreading contrails are much longer white lines which remain visible for a long time even after the plane disappears.

The air which the plane travels through is rather humid with a large amount of water vapor available to create a trail. Persistent spreading contrails are similar to non-spreading trails. Though, they spread out over a larger distance because of turbulence or other weather conditions. Their large area and life longevity make them the most likely to affect climate. Contrail cousins resemble contrails though differ slightly in the physical process which creates them.

One of the most common type of contrial cousins are the vapor trails which extend from the wingtips of a jet, typically during takeoff or landing. Weather permitting, if the pressure of the vortex at the end of the wingtip drops enough, a trail will form. Under the right conditions, liquid water forms drops inside the vortex making them visible.

Though, they quickly evaporate after they are created. Typical contrials seen behind airliners are not dangerous. Their main composition is pure water.

Jet fuel is also highly refined to remove as many contaminants as possible. Inside the engine, a large amount of gas must quickly flow through to the combustion chamber to keep the turbine spinning.

The fuel travels through small tubes within the engine at liters per second. The smallest imperfections can lead to a build up which can prove to be deadly. An engine overhaul is extremely expensive, reaching into the millions of dollars.