[meteorite-list] Re: Joshua Tree, maybe

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:25 2004
Message-ID: <200302060259.SAA17485_at_zagami.jpl.nasa.gov>

>YES. Have you taken the ALTITUDE of the jet stream into
>consideration? The top of the jet stream is at an altitude of
>about 14 km.

No, I haven't, and thanks for the analysis.

>Before the jet stream can start giving Shuttle tiles a ride, those
>tiles have to get down there. The jet stream is only about
>5 km thick; while the tiles are light, gravity still brings
>them down. I don't know what the freefall terminal velocity
>is for a tumbling tile, but I'd think it's at least 30 mph.
>At even that slow speed, a tile would only spend a little over
>6 minutes in the jet stream. The maximum jet stream velocity
>is about 400 km/hour during which time the tile could
>travel a little over 41 km. Joshua Tree is over 450 km away
>from the groundtrack, so you see why it really doesn't make
>any sense to consider it for debris heavier than a few
>ounces.

OK, let's assume then that the debris took a slight deviation
from the shuttle's flight path towards the south when it separated
from the shuttle. Could that be enough to account for the
additional distance to Joshua Tree? The debris field in
Texas/Louisiana is at least 380 miles by 230 miles, and
that was at a lower altitude over Texas.

Incidently, from the desciption of the item found in Joshua
Tree, it didn't sound like what was found there was a
shuttle tile:

  4-inch square object described as looking like a piece
  of exposed film. It has foil-like material on one side
  and apparent burn marks.

> so you see why it really doesn't make
>any sense to consider it for debris heavier than a few
>ounces.

On the other hand, this piece of film would be very light...
I guess they'll determine if it really came from
Columbia.

Ron Baalke
Received on Wed 05 Feb 2003 09:59:58 PM PST