[meteorite-list] POP QUIZ FRIDAYS ANSWER AND WINNER OF THE ORNANSMETEORITE

[John.L.Cabassi]

G'Day Shawn
Now that was a definite curve ball and a misunderstanding on my behalf. Your question was "How many meteorite falls are there with accurate tracking data on atmospheric passage?"  I think the key words are "meteorite" and "falls".  Correct me if I'm wrong. I found Almahata Sitta is one of the most accurate recorded falls of all time. 

I also see "interplanetary meteoroids and small asteroids" of your suggested reading. 

My question to you, regardless of the contest which I appreciate your generosity and my continued education; we have a conflict with meteoroids and meteorites. I'm interested to know in what you have posted, what meteorite falls make up this 13?

Can you elaborate on their names of what actually hit the ground as a meteorite?  Just curious. An over-active mind

Cheers
John Cabassi
IMCA # 2125

-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Shawn Alan
Sent: Wednesday, January 18, 2012 4:51 PM
To: Meteorite Central
Subject: [meteorite-list] POP QUIZ FRIDAYS ANSWER AND WINNER OF THE ORNANSMETEORITE


Hello Listers

Sorry for the delay been busy with other projects. I would like to give a shout out to the Mars meteorite and the finalized name :) cool stuff, cant wait to read about it in my MAPS. If people do not know what I am talking about go to http://www.meteoriticalsociety.org/ an join the CLUB it worth every penny.

Now back to the QUIZ

I would like to say thank you Listers for sending in your answer :) 

Question

How many meteorite falls are there with accurate tracking 
data 
on atmospheric passage?

Answer

13

If you like to read up on this keep on reading...........


Very low strengths of interplanetary meteoroids and small asteroids

 1. Olga POPOVA1,*, 
    2. Jiří BOROVIČKA2, 
    3. William K. HARTMANN3, 
    4. Pavel SPURNÝ2, 
    5. Edwin GNOS4, 
    6. Ivan NEMTCHINOV1,†, 
    7. Josep M. TRIGO-RODRÍGUEZ5 

Article first published online: 29 SEP 2011 
DOI: 10.1111/j.1945-5100.2011.01247.x 
© The Meteoritical Society, 2011
Issue 

Meteoritics & Planetary Science 
Volume 46, Issue 
10, pages 1525–1550, October 2011   


Abstract– We have assembled data on 13 cases of meteorite falls with 
accurate tracking data on atmospheric passage. In all cases, we estimate the 
bulk strength of the object corresponding to its earliest observed or inferred 
fragmentation in the high atmosphere, and can compare these values with measured 
strengths of meteorites in the taxonomic class for that fall. In all 13 cases, 
the strength corresponding to earliest observed or inferred fragmentation is 
much less than the compressive or tensile strength reported for that class of 
stony meteorites. Bulk strengths upon atmospheric entry of these bodies are 
shown to be very low, 0.1 to approximately 1 MPa on first breakup, and maximal 
strength on breakup as 1–10 MPa corresponding to weak and “crumbly” objects, 
whereas measured average tensile strength of the similar meteorite classes is 
about 30 MPa. We find a more random relation between bulk sample strength and 
sample mass than is suggested by a commonly used empirical power law. We 
estimate bulk strengths on entry being characteristically of the order of 
10−1–10−2 times the tensile strengths of recovered 
samples. We conclude that pre-entry, meter-scale interplanetary meteoroids are 
typically highly fractured or in some cases rubbly in texture, presumably as a 
result of their parent bodies’ collisional history, and can break up under 
stresses of a few megapascals. The weakness of some carbonaceous objects may 
result from very porous primordial accretional structures, more than fractures. 
These conclusions have implications for future asteroid missions, sample 
extraction, and asteroid hazard mitigation.

source: http://onlinelibrary.wiley.com/doi/10.1111/j.1945-5100.2011.01247.x/abstract

I would like to congratulate Brett W for being the first to submit the correct answer because there was on 7th Lister that got the answer right. He will be getting a free Ornans 5mg fragment.

Till next time keep on rocking

Shawn Alan 
IMCA 1633 
eBay Store 
http://www.ebay.com/sch/ph0t0phl0w/m.html?          
______________________________________________
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