[meteorite-list] Smoke Trails

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sat, 5 Nov 2011 01:45:39 -0500
Message-ID: <F645608CB92245E8B2A1BF5A13CDD6E6_at_ATARIENGINE2>

Dear Doug, List,

> Not a good idea to skydive that high!

Can I point you to Joseph Kittinger?
http://en.wikipedia.org/wiki/Joseph_Kittinger

He holds the altitude record for a parachute
jump at 102,800 feet (31.3 km). He fell for four
minutes and 36 seconds, reaching a maximum
speed of 614 miles per hour (988 km/h) before
opening his parachute. Oh, and he jumped
from a balloon, so he holds the record for the
highest balloon ascent, as well as longest fall
and fastest speed. In 1984, he made the first
solo gas balloon crossing of the Atlantic.

He didn't leave a contrail or a smoke trail,
though.

The principal physical difference between them
is that a contrail is essentially gaseous, just as
the atmosphere is, while a smoke trail is a
dispersed solid, made of very small rock particles
and few to no gases (by weight).


Sterling K. Webb
-------------------------------------------------------------------
----- Original Message -----
From: "MexicoDoug" <mexicodoug at aim.com>
To: <geeg48 at msn.com>; <Meteorite-list at meteoritecentral.com>
Sent: Saturday, November 05, 2011 1:14 AM
Subject: Re: [meteorite-list] Smoke Trails


> You'd have to look at the specific case and if what you say is
> generally true, here's a few ideas to kick around:
>
> Wind speed. Planes fly up to about 10 km for a reason; above that
> wind speeds can easily triple. Bolides leave smoke trails starting
> around 70 km altitude downward. Above 70 km or so it is mainly
> incandescence (a photo-electric process which quenches itself quicker,
> like lightning but is a bit more persistent due to the higher altitude
> reducing the quenching rate since the mean free path is longer.
>
> Particle (size, density, phase). If the result of fuel combustion is
> light, fine soot and gases and that of a meteor a larger particulate
> mixture with denser individuals ...
>
> Altitude (atmospheric density). Less air = less suspension effects.
> An object falls faster at higher altitude by a factor of
> sqrt[(do-da)/da)] where do is the density of the object and da is the
> density of the air. That's basically sqrt(do/da). So, if the
> atmosphere is 100x denser at 10 km than it is at 50 km, it will fall
> sqrt(100) = 10 X times faster. Not a good idea to skydive that high!
>
> Kindest wishes
> Doug
>
>
>
>
>
>
> -----Original Message-----
> From: GREG LINDH <geeg48 at msn.com>
> To: pshugar <pshugar at messengersfromthecosmos.com>
> Cc: meteorite-list <meteorite-list at meteoritecentral.com>
> Sent: Sat, Nov 5, 2011 12:53 am
> Subject: Re: [meteorite-list] Smoke Trails
>
>
>
> I'm not a scientist, but I think the contrail has more moisture in
> it, and
> this could cause it to linger longer than the meteorite trail. Just a
> thought.
>
>
>
> Greg L.
>
>
>
>
>
> ----------------------------------------
>> From: pshugar at messengersfromthecosmos.com
>> To: meteorite-list at meteoritecentral.com
>> Date: Fri, 4 Nov 2011 20:41:38 -0700
>> Subject: [meteorite-list] Smoke Trails
>>
>> Why does a jet's contrail last for quite a while,
>> yet a meteorite's trail disapears so very quickly?
>> Pete Shugar
>> IMCA 1733
>>
>>
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Received on Sat 05 Nov 2011 02:45:39 AM PDT