A question for commercial pilots.

[The Backlash Cometh]

I'm posting this in GD for the traffic.

My daughter and I saw something incredibly weird yesterday and I wondered what created the phenomenon. As we were driving along, I looked up in the sky and there was a perfectly straight dark line that ran overhead and sunk straight into the horizon. I asked my daughter if she could see it too and she said she did. Just as I was about to wonder out loud what it was, I saw a commercial plane on the same dark track. It was overhead and moving along in the exact same path towards the horizon, just like a traffic lane.

The sky was a solid blue, except for the dark line. So, what causes that perfect line?

[SpiralHawk]

1. Hmmmm? Check this out.

FORMER CANADIAN MINISTER OF DEFENCE ASKS CANADIAN PARLIAMENT
TO HOLD HEARINGS ON RELATIONS WITH ALIEN "ET" CIVILIZATIONS
PRWEB
November 24, 2005

http://news.yahoo.com/s/prweb/20051124/bs_prweb/prweb314382_1

A former Canadian Minister of Defence and Deputy Prime Minister under Pierre Trudeau has joined forces with three Non-governmental organizations to ask the Parliament of Canada to hold public hearings on Exopolitics -- relations
with “ETs.”

By “ETs,” Mr. Hellyer and these organizations mean ethical, advanced
extraterrestrial civilizations that may now be visiting Earth.

On September 25, 2005, in a startling speech at the University of Toronto that caught the attention of mainstream newspapers and magazines, Paul Hellyer, Canada’s Defence Minister from 1963-67 under Nobel Peace Prize Laureate Prime Minister Lester Pearson, publicly stated: "UFOs are as real as the airplanes that fly over your head."

[The Velveteen Ocelot]

2. I'm only guessing that what you saw was a vapor trail that was backlighted

by the sun. There is nothing visible in the sky that commercial aircraft follow; all navigation is done electronically. The fact that the airplane you saw seemed to follow the visible line just suggests that it was on the same airway (an electronic "road" in the sky) as the airplane that created the vapor trail. I can't think of any other explanation.

[The Backlash Cometh]

5. I'm sure it's an established airway. The planes do regularly follow

the road that I was traveling on.

Here is what I was really thinking: I thought that dark line broke through the "sky," and I thought I could see space in that line. What I was wondering was, is that established commercial path creating some kind of deterioration in the ozone?

[Aviation Pro]

3. What you saw was a contrail from one plane....

....and another following enroute. The horizontal seperation between these planes was no less than 5 nautical miles. The contrails are ice crystals that form from the exhaust of the turbofan engines. (I'd go deeper into the explanation, but I don't think anyone wants a meteorology class here).

[MaineDem]

6. And the line appeared straight because of lack of winds?

I would assume many contrails dissipate in the winds and appear irregular or disappear completely.

We see a lot of the transatlantic jets' contrails. Sometimes the sky looks like a reenactment of the Battle of Britain.

[The Backlash Cometh]

9. The lack of wind may be a factor, but this was not a weak smokey

line that would have dissapated with wind. At least, it did not appear to be. It was very strong and the edges were very defined.

[MindPilot]

12. The conditions at 35 or 40 thousand feet is very different

than here on the ground. I'm guessing in this particular case the winds aloft--which can frequently be well over 100mph--happened to be closely aligned with that particular airway so the contrail didn't dissipate be fore the next aircraft came along. It's also very cold up there so the ice crystals that form the contrail hang around for a while. Given the slow dissipation, it probably maintained a high content of exhaust gasses giving it the dark appearance.

I seriously doubt it was any more than that; and I don't think a hole in the ozone would be visible to the naked eye from the ground anyway.

[The Backlash Cometh]

13. Thanks. I'm reassured about your comment regarding the visibility

of ozone depletion from ground level. It makes sense that I wouldn't be able to see a wing-span deep seam in the sky from ground level.

[The Backlash Cometh]

7. Are there any pictures of contrails?

I've seen plenty of smokey lines with broken edges, but this was not that.

[Aviation Pro]

18. Google Images is our friend....

[The Backlash Cometh]

19. Okay, those were not like them at all.

There was one darkish "road" with defined edges that ran from above us, to straight into the horizon in front of us. It exactly looked like it was going to fall into the treeline, but of course, since the earth is contoured, it doesn't actually fall into the ground, just moves perpendicular until it turns with the horizon.

I believe, of all the explanations given, the shadow explanation makes the most sense. A shadow of invisible crystals that were left behind from a previous plane?

There was another plane that was making its way into the "road" that had the same contrails as your photo. The plane was following the dark path, just like a car drives on the road.

[Aviation Pro]

21. You were looking at a jet airway....

...and the contrails that the other plane was following was left by a previous aircraft.

[philb]

22. contrails normally have uneven edges and are not perfectly straight

due to wind currents being uneven, etc.

[Skittles]

20. LOL

my dad was a meteorologist and if you ever asked him anything about the weather you'd get that class! :D

[MindPilot]

4. What time of day and what were the weather conditions?

I'm trying to figure out what conditions would cause the contrail to be darker than the surrounding sky. Usually it has to do with the position of the sun combined with your visual angle. Other factors may be high level particulates of dust, smoke or other pollutants.

[The Backlash Cometh]

8. Beautiful clear blue sky; about 70 plus degrees, and it was

10:30 in the morning.

[Jakey]

10. It's possible that...

what you observed was the shadow of a contrail on an ultra-thin high altitude cloud layer. Was there also a visible contrail from the aircraft? I assume there was as it would be difficult to spot a commercial airliner at cruise altitudes without one.

[The Backlash Cometh]

11. Good question.

The commercial plane that I saw was leaving the usual white smokey trail. And yes, I spotted it because of the white trail. Otherwise it was a very small silver thing that could have been easily overlooked.

[Jakey]

15. Sounds like a shadow then...

and, just to clarify, contrails are actually frozen water vapor (frozen steam if you will) that are produced when the air being exhausted after combustion contains enough water vapor to make it visible when it freezes, which takes but a moment at the super-cool temperatures at high altitude.

You can see this easily with a pair of binoculars on a clear day when contrails are being produced. Note that the area immediately behind the engines appears clear and the contrail appears to "form"
several yards behind the engines. That's the time it takes for the water vapor to freeze and become visible as ice crystals.

[MindPilot]

14. Ahh, a shadow!! Most likely scenario...

One of the more beautiful sights I ever experienced was crossing at about 45 degrees between two contrails on a crystal-clear full moon night.

[Rufus T. Firefly]

16. Chemtrails!!!

/Tinfoil hat off

[The Backlash Cometh]

17. How about a shadow of chemtrails?

I like the shadow explanation. Thanks to everyone who posted.