[meteorite-list] British Study Attempts to Calculate Odds ofBeingHit By a Meteorite

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Mon Jul 31 18:21:55 2006
Message-ID: <002401c6b4ef$b7d8a5d0$954ee146_at_ATARIENGINE>

Hi,


    This what I get for doing arithmetic at 3 in the am.
Off by a factor of two, but so are you. Since you can't
decide where in the circle of destruction you will be,
the mean maximum distance would be the radius of the
circle, or 1358 feet, the circle always being defined as
having its center at the impact point.
    That's about a quarter mile. Let's see. Up to 6 tons
TNT force. 100's of tons of ejecta at 100's of mph.
Ok, you stand on the edge of the circle. I'll take those
bleacher seats. We'll both have video cameras, and I
know you'll get the better pictures, but I'll feel safer.
    The question of target ground composition is just
luck. Unconsciously, I assumed limestone bedrock
not far down. (There's a quarry right in the dead
center of my town...) Maybe I'd feel safe it was all
dirt... And IF we knew the impactor was an iron.
    But it's a one ton stone (all stone; no mesosiderites)
fragment impacting at hypersonic speed, I don't want
to be only 1/4 mile away regardless of target. I'll be
in the bleachers, with my face painted in Team
Meteorite colors, waving the Meteorite flag,
video camera (Zoom X10) at the ready.
    But if it's one pound stones falling at 120 mph,
I'll be running around the strewn field with little red
tag-flags, GPS, camera, baggies... and a big hard hat.


Sterling K. Webb
----------------------------------------------------
----- Original Message -----
From: "Darren Garrison" <cynapse_at_charter.net>
To: "Sterling K. Webb" <sterling_k_webb_at_sbcglobal.net>
Cc: "Meteorite List" <meteorite-list_at_meteoritecentral.com>
Sent: Monday, July 31, 2006 9:59 AM
Subject: Re: [meteorite-list] British Study Attempts to Calculate Odds
ofBeingHit By a Meteorite


On Mon, 31 Jul 2006 03:59:04 -0500, you wrote:

>Hi,
>
> I think that, by the indicated weights, they are referring to
>the mass of the object to reach the ground at speed. You will
>note that they say of the eight 25 pounders "if they landed," but
>the vast majority never would.

But meteortes in the 25 pound range have been recorded to land near people
before-- without killing everone within "the size of a backyard garden" (or
whatever the phrasing was) of them.

>I had no trouble getting a one-ton iron to the ground with
>an impact energy release of 2600 pounds of TNT, hitting
>at 500 mph. How close do you want to be to that? A 133
>acre circle means that you couldn't get further than about
>650 feet away from the center of the impact zone. There's

Some googling shows that 133 acres is 5793480.00 ft2. Since pie are square,
then that would mean the safe distance would be 1358 feet, giving a "kill
zone"
diameter of 2716 feet. I admit that I don't have the math to back it up, it
just "seems" like a huge area for a piece of iron roughly on the same scale
as
Steve Arnold's oriented Brenham to kill everything. Maybe if it hit solid
rock
and shattered into sharpnel, but not if it hits soft ground.
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Received on Mon 31 Jul 2006 06:21:49 PM PDT