[meteorite-list] Smoke Trails

[Richard A. Kowalski]

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