RE : [meteorite-list] Prospecting for meteorites
Hi, Thanks Sterling for the additionnal info about the Chinguetti meteorite story. I suggest to say that there is no more controversy about the existence of the huge mass and to stop spending time searching it. The dynamic of fall teaches that any mass larger than 200 tons will vaporize upon landing. The possible mass of the Chinguetti hill is over thousand of tons. For me it is physically impossible the find this huge mass. Then it is true that a meteorite was found nearby that hill and that the sun burnt rocks in the hot Sahara are covered with desert varnish, often very black and sometimes similar to slightly alterated fusion crust. The confusion was possible before we had knowledge of Eugene Shoemaker works about impact craters. My 2 cents. Best regards Michel FRANCO Its existence is still a controversy. Oddly, the supposed fragment is widely accepted as a real meteorite, while the mass from which it was removed is not, which seems a little paradoxical. Sterling K. Webb -- [EMAIL PROTECTED] wrote: I dream to find a similar one, somewhere ... if anyone has a clue where to prospect, please share it with me, off list, other wise I will have to charter a 380! Bonjour Michel, hello List, The enormous Chinguetti main mass (said to be 100 m long and 45 m high) in the desert of Adrar (Mauritania) is still waiting for you to go and get it ;-) Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: RE : [meteorite-list] Prospecting for meteorites
Hi, Some decades ago, John S. Lewis calculated that the largest IRON mass that could survive to reach the surface of the Earth was under 100 tons. This was making all the ideal assumptions: low entry velocity, low entry angle, flattened shape. He suggested that HOBA, which is about 60 tons, was originally that mass. The soil surrounding it is rich red oxydized shaley dirt and probably formed from the erosion product of a larger HOBA than today's 60 tons. The largest STONE mass, by the same calculation, would be only roughly 40 tons, but since stones are poorly consolidated, they are unlikely to be able to resist fragmenting, which seems to be the case. If there was a 40 ton stone meteorite, it would be a mass equivalent to a sphere about 10 feet in diameter (3+ meters). Objects shatter if a shock wave (like a re-entry shock wave) exceeds the speed of sound in the material of the object. Stoney meteorites that have been tested demonstrated a slow internal speed of sound. Hence, it is likely that most large stoney meteorites are shattered by their own re-entry shock waves! Sterling K. Webb - michel FRANCO wrote: Hi, Thanks Sterling for the additionnal info about the Chinguetti meteorite story. I suggest to say that there is no more controversy about the existence of the huge mass and to stop spending time searching it. The dynamic of fall teaches that any mass larger than 200 tons will vaporize upon landing. The possible mass of the Chinguetti hill is over thousand of tons. For me it is physically impossible the find this huge mass. Then it is true that a meteorite was found nearby that hill and that the sun burnt rocks in the hot Sahara are covered with desert varnish, often very black and sometimes similar to slightly alterated fusion crust. The confusion was possible before we had knowledge of Eugene Shoemaker works about impact craters. My 2 cents. Best regards Michel FRANCO __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Prospecting for meteorites
Hi, For List members not familiar with the Chinguetti story, see this web page (and following pages) which recount the story: http://www.channel4.com/history/microsites/E/ends/meteorite1.html Theodore Monad's paper: http://adsabs.harvard.edu/abs/1989CRASM.309..547M A picture of the supposed fragment: http://www.meteoritestudies.com/protected_CHINGUET.HTM Google will get you 432 hits if you want more... Its existence is still a controversy. Oddly, the supposed fragment is widely accepted as a real meteorite, while the mass from which it was removed is not, which seems a little paradoxical. Sterling K. Webb -- [EMAIL PROTECTED] wrote: I dream to find a similar one, somewhere ... if anyone has a clue where to prospect, please share it with me, off list, other wise I will have to charter a 380! Bonjour Michel, hello List, The enormous Chinguetti main mass (said to be 100 m long and 45 m high) in the desert of Adrar (Mauritania) is still waiting for you to go and get it ;-) Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
RE : [meteorite-list] Prospecting for meteorites
Thanks Bernd, Yes it is an amazing story. It has now been proved that this meteorite is a tale. A nice book in French Le fer de Dieu ( Actes Sud editor) explains all the searches of this object, book by Théodore Monod and Brigite Zanda. ( both Muséum National d'Histoire Naturelle de Paris). Théodore spend most of his life in the Sahara and collected 20 000 scientific specimen, including one Meteorite. Best regards Michel. -Message d'origine- De : [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] De la part de [EMAIL PROTECTED] Envoyé : mercredi 16 novembre 2005 17:24 À : Meteorite-list@meteoritecentral.com Objet : [meteorite-list] Prospecting for meteorites I dream to find a similar one, somewhere ... if anyone has a clue where to prospect, please share it with me, off list, other wise I will have to charter a 380! Bonjour Michel, hello List, The enormous Chinguetti main mass (said to be 100 m long and 45 m high) in the desert of Adrar (Mauritania) is still waiting for you to go and get it ;-) Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
