# What is this trail in the sky? **URL:** \ **Category:** Factual Questions\ **Created:** [December 17, 2013, 2:35am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522 "2013-12-17T02:35:03Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![An\_Gadai](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@An\_Gadai](https://boards.straightdope.com/u/An_Gadai)\ **Post date:** [December 17, 2013, 2:35am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/1 "2013-12-17T02:35:03Z")
An acquaintance of mine posted [an image of this trail](http://instagram.com/p/iAYLElAGvj/) seen above Co. Kerry in Ireland. Can anyone tell me what would make that trail? ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [December 17, 2013, 2:52am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/2 "2013-12-17T02:52:50Z")
Looks like a standard contrail that’s been blown about a bit by high-level winds. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [December 17, 2013, 2:54am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/3 "2013-12-17T02:54:41Z")
Looks like an ordinary straight contrail that’s been distorted by irregularly moving air to me. ---
**Author:** ![An\_Gadai](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@An\_Gadai](https://boards.straightdope.com/u/An_Gadai)\ **Post date:** [December 17, 2013, 3:17am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/4 "2013-12-17T03:17:49Z")
Grand, thank you folks. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [December 17, 2013, 3:34am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/5 "2013-12-17T03:34:09Z")
As soon as you see anybody write “surely a plane can’t do that” the answer is always, 100% of the time, “a plane did that.” ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 17, 2013, 3:42am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/6 "2013-12-17T03:42:23Z")
Alternatively, it could be a goose smoking a really big spliff. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [December 17, 2013, 4:54am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/7 "2013-12-17T04:54:25Z")
A Great White Sperm. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [December 17, 2013, 4:57am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/8 "2013-12-17T04:57:31Z")
> [@panache45](#): > > A Great White Sperm. The cumming of the Lord? ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [December 17, 2013, 5:01am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/9 "2013-12-17T05:01:20Z")
Patty Wagstaff practicing? [http://en.wikipedia.org/wiki/Patty\_Wagstaff](http://en.wikipedia.org/wiki/Patty_Wagstaff) ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [December 17, 2013, 5:10am UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/10 "2013-12-17T05:10:11Z")
> [@Askance](#): > > Looks like a standard contrail that’s been blown about a bit I’m unconvinced. Winds variable enough to cause that much “squiggle” should also have caused the contrail to diffuse more than this one has. And the abrupt end is not something an airplane can readily produce. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [December 17, 2013, 12:15pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/11 "2013-12-17T12:15:33Z")
It looks more like a photography artifact than something actually in the sky. ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [December 17, 2013, 1:11pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/12 "2013-12-17T13:11:25Z")
I can’t see the link for some reason (stupid firewall) but I have a photo somewhere of a contrail involving great whirling loops across the sky. At a guess it was caused by a plane in a holding pattern for a not-too-distant major airport. Contrails are cool. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [December 17, 2013, 2:01pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/13 "2013-12-17T14:01:33Z")
> [@Xema](#): > > I’m unconvinced. Winds variable enough to cause that much “squiggle” should also have caused the contrail to diffuse more than this one has. And the abrupt end is not something an airplane can readily produce. Contrails can end abruptly since different layers of air can have different moisture contents. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [December 17, 2013, 2:19pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/14 "2013-12-17T14:19:06Z")
A horizontal contrail tends not to wiggle that much, but a vertical one can really get wobbly quickly. If it was a fast climbing jet (which might easily be the case given the location), this could easily happen. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [December 17, 2013, 2:21pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/15 "2013-12-17T14:21:18Z")
> [@Quartz](#): > > Contrails can end abruptly since different layers of air can have different moisture contents. Yes, but this example looks unusually abrupt. Add in the excessive squiggle, and it seems suspicious. ---
**Author:** ![Sicks\_Ate](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@Sicks\_Ate](https://boards.straightdope.com/u/Sicks_Ate)\ **Post date:** [December 17, 2013, 2:35pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/16 "2013-12-17T14:35:26Z")
> [@Askance](#): > > Looks like a standard contrail that’s been blown about a bit by high-level winds. Chemtrail. You mean **chem** trail. We’re all being experimented upon. > [@Johnny\_L.A](#): > > The cumming of the Lord? Revelation 22:12 “Behold, I come quickly…” ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [December 17, 2013, 3:10pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/17 "2013-12-17T15:10:44Z")
> [@Xema](#): > > Yes, but this example looks unusually abrupt. Add in the excessive squiggle, and it seems suspicious. My first thought was that it was a scratch or a hair but if you look, you’ll see that to the left of centre it’s partially obscured by the lower-level cloud. So my guess is that it’s from an aircraft coming in to land or taking off from Cork or Dublin airport. ---
**Author:** ![lance\_strongarm](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lance\_strongarm](https://boards.straightdope.com/u/lance_strongarm)\ **Post date:** [December 17, 2013, 5:25pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/18 "2013-12-17T17:25:03Z")
Oh, please, people. It’s obviously evidence of an alien spacecraft. No other explanation is possible. ---
**Author:** ![Zyanthia](https://avatars.discourse-cdn.com/v4/letter/z/d6d6ee/32.png) [@Zyanthia](https://boards.straightdope.com/u/Zyanthia)\ **Post date:** [December 17, 2013, 5:30pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/19 "2013-12-17T17:30:28Z")
Are you all sure it’s not Smaug getting is daily exercise? ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [December 17, 2013, 11:13pm UTC](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522/20 "2013-12-17T23:13:51Z")
I was skeptical that it was a wind blown contrail at first because I’m a bit of a skywatcher and have never seen one distorted quite like that, but the first hit in a google image search for “squiggly contrail” is [almost its twin](http://geekswithblogs.net/jjulian/archive/2007/12/17/117790.aspx), and they have two photos taken some seconds or minutes apart showing it get more squiggly too. [Next page](https://boards.straightdope.com/t/what-is-this-trail-in-the-sky/676522.md?page=2)