[meteorite-list] Smoke Trails

From: Richard A. Kowalski <kowalski_at_meteoritecentral.com>
Date: Sat, 05 Nov 2011 00:40:38 -0700
Message-ID: <4EB4E876.1020806_at_lpl.arizona.edu>

Peter,

contrails are produced by water vapor, usually in the exhaust ejected
into various natural vapor concentrations at cruise altitude. If the
concentrations are higher, the trail lasts longer.


Spend some time examining the trails of passing aircraft. As the weather
changes over the months you'll notice the contrails do too. When the air
at altitude is dry no, or very short trails will be created. When the
vapor is just a little denser you'll notice thin trails that extend from
less than a kilometer or two kilometers or so before they vanish. Higher
still & the trails persist for many minutes or hours.

Check out wiki:

http://en.wikipedia.org/wiki/Contrails


As Doug explains the trail of a bolide is not the same. He does not
mention winds at these altitudes, but they can be calm or high. High
winds and the suspended particles rapidly break up. Smooth air and they
can retain relatively similar positions for extended periods of time.

I've saved a few images of meteor "smoke" trails I've come across while
observing. The smoke trails are interesting because of the winds at
altitude. They can be found on my work webpages at:

http://www.lpl.arizona.edu/~kowalski/interesting_events.html

This year's Orionids were fun to watch via the cloud camera on the
telescope and on the survey plates, but did not think any were worth saving.

I do have one of my early time lapse series during a moonlit night that
contains a nice bolide flash. It illuminates the landscape and you can
clearly see the shadows cast by it. About 30 minutes later you see the
smoke trail enter the top of the frame and continue eastward for about
45 minutes until I can't resolve it any longer, if I recall these
numbers correctly.


I've meant to rebuild that time lapse with better processing techniques,
but my time to really neat things to do ratio is not favorable.

-- 
Richard A. Kowalski
Senior Research Specialist
Catalina Sky Survey
Lunar & Planetary Laboratory
University of Arizona
Tucson, Arizona

Received on Sat 05 Nov 2011 03:40:38 AM PDT