[meteorite-list] Meteorites, their parent bodies, strewn fields, and beta

[Chris Peterson]

Hi Ed-

Unless you also have some information about the trajectory of the original 
fireball, analyzing a strewn field doesn't tell you much. The shape and 
orientation of the strewn field is strongly affected by winds during the 
fall, which can completely erase the details of the breakup. When analyzing 
fireballs, a good measure of porosity comes from the optical efficiency. 
That can be calculated from the brightness and the mass. The latter is 
estimated either from the acoustic energy (if also captured by infrasound 
detectors), or by examining the dv/dt profile.

Chris
________________________________
Chris L Peterson
http://www.cloudbait.com


----- Original Message ----- 
From: "E.P. Grondine" <epgrondine at yahoo.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Saturday, April 07, 2007 9:33 PM
Subject: [meteorite-list] Meteorites, their parent bodies, strewn fields,and 
beta


> Hi everyone -
>
> My apologies once again for not yet writing a full
> thanks you note to everyone from Tucson, but I hope
> you'll understand...  I've already mentioned Mexico
> Doug and some others, but let me also thank Impactika,
> Anne Black, and Chladnis's Heirs, for the fine
> specimens.  There's others who I need to thank, but I
> don't think that this is the place to do it, for
> reasons which they know.
>
> The reason for this note is that this is important. I
> hope you all know that meteorites are more dense than
> their parent bodies.  I can't point you to an easy
> internet site where you may learn this if you don't.
> Now that this difference in density is ascribed to
> "porosity", spaces in the parent bodies.
>
> It has turned out that the momentum imparted to a
> parent body when it is hit by a kinetic mass is far
> greater than the mere addition of moments, due to a
> jet reaction which occurs when the parent body is hit.
> This multiple of momentum is called "beta", and it
> appears to be dependant on "porosity".
>
> So how can you get some good estimates of "beta", of
> "porosity"? I think that some answers to these
> questions may be gained by studying strew field
> distributions for the different types of meteorites.
>
> Why? Because those strewn fields, which show a small
> part of a parent body explodes when it hits the
> atmosphere, are also dependant on porosity.
>
> Does this make sense to all of you experts here?
>
> good hunting,
> Ed
/meteorite-list