[meteorite-list] Updated Lorton trajectory

From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Wed, 27 Jan 2010 10:37:06 -0700
Message-ID: <6E32793001A348E8BCF429239D18A99E_at_bellatrix>

Hi Mike-

Meteorites are falling at terminal velocity for miles before they hit. They
rapidly lose all of their original velocity components. So yes, this
particular meteorite would have behaved the same regardless of its entry
characteristics.

The ground is hard... really, really hard. In many cases, you can consider
it to be essentially incompressible. So even a heavy object landing hard and
fast can easily find itself sitting in nothing more than a shallow divot.

Roofs and ceiling, on the other hand, are generally pretty flimsy. A small,
dense object traveling at 100 m/s can rather easily pierce such structures.

Meteorites do chip stone and concrete when they land. It really doesn't take
all that much energy to do that. Toss a stone off a cliff onto rocky ground
and you'll see plenty of chipping, and the tossed stone probably won't even
have reached terminal velocity.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message -----
From: "Mike Hankey" <mike.hankey at gmail.com>
To: "Chris Peterson" <clp at alumni.caltech.edu>
Cc: "meteorite list" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, January 27, 2010 10:12 AM
Subject: Re: [meteorite-list] Updated Lorton trajectory


> George/Chris,
>
> I wasn't sure about this hence the ? , at the end of the sentence,
>
> but conceptually i was thinking a steeper entry angle would result in the
> meteorite reaching the ground with more velocity after traveling less
> distance, but I guess I'm wrong about this.
>
> Chris to your point -- it wouldn't make a difference -- the meteorite
> would
> have punched through the roof and cracked the cement floor regardless of
> the
> entry angle?
>
> I guess I've been under the assumption that meteorites are generally
> sitting
> ontop of the ground and don't hit the ground with enough force to bury
> themselves. But I can't help thinking that if this 300g rock hit a dirt
> field with the same force that it would just be lying ontop of the grass
> and
> not buried under the ground. If it had enough force to break through a
> roof,
> a firewall and crack a cement floor wouldn't the same rock be under the
> ground if it hit the dirt?
>
> Thanks,
>
> Mike
Received on Wed 27 Jan 2010 12:37:06 PM PST