[meteorite-list] getting oriented on orientation

[Mike Bandli]

Great suggestions, Darryl. I would go even a little less complicated and suggest a 3 number rating system. Here are some quick, nut-shell definitions:

O3 - Completely oriented: Obvious and conclusive evidence that the meteorite stabilized during entire flight.

O2 - Partially Oriented: Evidence that the meteorite stabilized during most of flight, but also tumbled of axis.

O1 - Some Orientation: Evidence that the meteorite stabilized briefly at one or several different points during flight, but tumbled majority of flight.

No Orientation - If no orientation is present, then there is probably no need to mention it in description.

Other considerations: Where does 'dual orientation' fit in? I have had numerous Sikhotes that have had 'bullets' or 'buttons' on both ends - evidence that the they flopped like a pancake and partially stabilized on both opposing edges.

Keep the suggestions coming.

Best,

Mike Bandli
www.Astro-Artifacts.com

 -------------- Original message ----------------------
From: Darryl Pitt <darryl at dof3.com>

> 

> topic:  grading system for orientation

> 

> just trying to get things started off here.

> 

> i don't believe there should be 10-grades of orientation, as was  

> suggested, as it seems too broad and results in a situation that is  

> similar to the one before us:  the too-liberal invocation of the  

> term.  might i suggest a scale of O1-O4 or perhaps to O5 at the most.

> 

> it would seem the determination of the extent of orientation should  

> be based on the presence of a number of specific characteristics and  

> the extent to which such characteristics are manifest.  i beseech the  

> input of scientists who are expert in eliminating the ambiguities in  

> such a grading system.

> 

> let's start with some characteristics of orientation that come to  

> mind....

> 

> evidence of ablation

> presence of flow lines/rivulets

> flow lines radiating in all directions off a single coordinate

> elongated parallel regmaglypts radiating off a single coordinate

> distinctly different morphologies of the obverse and reverse

> evidence of bubbling in the low-pressure zone (reverse)

> parabolic curvature of lead face (including small parabolas at tip of  

> oriented "bullets")

> "lipped" edges and evidence of molten material having ablated over  

> the edge of such lips

> 

> 

> please add or subtract to the list.  maybe some characteristics  

> should be weighted more than others and then there is the quandary of  

> quantifying the extent of such characteristics.

> 

> i hope this helps to start things off.  and i hope we're able to get  

> this resolved and get....oriented on orientation.

> 

> all best / d,

> 

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