Re: [meteorite-list] ?????Monahans-1998????????
Monahans 1998 fall was H5 br, 2.587 kg, older Monahans 1938 IIF, 27.9 kg. pekka s Pete Shugar kirjoitti: Someone want to check out Ebay auction # 310038556946 They claim just over 6 grams of Monahans 1998 starting at 0.99 and no bids so far. They don't look like any meteorite I've ever seen. Looks more like some old Roman or Greek coins. Pete __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list -- Solar Gems Pekka Savolainen Jokiharjuntie 4 FI-71330 Rasala FINLAND GSM + 358 400 818 912 [EMAIL PROTECTED] Member of IMCA 5776 www.imca.cc __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Atmospheric ablation marks on Tektites?
Sean & all, This is whipping a dead horse, but I hate to see confusion perpetuated any more than it needs to be. You wrote "The vast majority agrees they [tektites]are of cosmic origin--" Surely you mistakenly left out the "NOT"? Or maybe you use the word "cosmic" to include everything in the cosmos, which includes earth. Most commonly though, other people use "cosmic" to suggest something not of the earth. There is virtually no debate about LDG. Most listees know that we can now point to a specific source crater (Kebira) discovered a couple of years ago. You have and have seen "splash-form" LDG pieces??? Please don't say stuff like that in a public forum where it can only confuse those trying to learn. I am sure it would take about 5 minutes to find a buyer willing to pay over $1000 for even a small (but convincing) example, and I might well buy it myself. Maybe consider adding the term "pseudo-splashform" to your pseudo-regmaglypt theme. "Tektite and impactite - different animals". Yes, the words mean different things, but they are not unrelated. Virtually all (living) students of the subject would accept that tektites are a subdivision of impactites. Tektites are impactites, but not all impactites are tektites. Deep enough, Norm http://tektitesource.com --- "Sean T. Murray" <[EMAIL PROTECTED]> wrote: > Michael, > > Yep - it's amazing that something so simple as a > piece of glass has caused > so much churning for over 100 years. The vast > majority agrees they are of > cosmic origin, most believe that they are from > impacts on earth, but there > are still those that believe the moon is directly > involved. I've also read > some other bizarre ideas - the coolest of them (to > me) was the idea that the > reason tektites are not always formed is that maybe > they come from the > impact of a huge ball of silica glass that slams > into earth - A big > meteorite just made of glass... how cool would that > be. > > So far, everything I read simply states that > tektites come from multiple > sources. And don't worry about the "noob" stuff - > I've only been diving > into this for a few months, so I'll still say > something way off base (as > Doug points out with my "still a lot of debate" > comment.) It's almost > always wrong to make any general statement about > tektites as a whole... the > LDG debate is still ongoing as to how it was formed, > but most people tie it > to an impact event, and as an impactite. I've seen > pictures (and have a few > pieces) of LDG that show some of the splash-form > types of characteristics of > tektites, but nothing with a "crust" or a true > regmaglypts. > > - Tektite and impactite - different animals. > > - LDG and Darwin glass - Terrestrial - it really > helps that there are > inclusions that are of the local material stuck in > them. They also have a > slightly higher concentration of water (in ppm) that > make them different > than a true tektite. The shaping that is seen in > those glasses is not as > nearly as convincing as the Australasian glasses. > > -Ventifacts is the more correct answer. But > considering the company that > tektites keeps with our other cosmic collectibles, > I'm gonna stick with > pseudo-regmaglypts until someone beats me up. > > - Yes - there are a lot of good documentation that > spells out the > composition of tektites. (Get Povenmire's book and > McCall's book). The > chemical composition of the tektites is the thing > that really drives a lot > of the controversy. The glass, in many cases, is > very pure and free of > water - it's hard to say how it was made since it > breaks a few of the glass > making rules and regulations :) They have found > tektite like material on > the moon (if it was found here on earth no one would > have argued that it was > not a tektite), but they are very small. It was > thought that the first > trips to the moon would have seen and brought back > big, standard lots of > tektites if that is where the originated - but they > did not. many people > changed their minds on the lunar origin after the > moon landings. When they > found microtektites on the moon, they ascribed them > to impacts on the > moon... after all, it is generally accepted that the > moon and the earth are > made from each other, so there will always be > similarities. > > Another fun origin note: > John O'Keefe was another of the proponents of the > lunar origin of tektites. > He died in 2000, and on his funeral program he had > wanted the following > phrase added: > "Tektitae De Luna Sunt!" - "tektites are from the > moon!" > That's conviction. > > Sean. > > - Original Message - > From: "Michael Gilmer" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Cc: > Sent: Saturday, April 05, 2008 11:07 AM > Subject: Re: [meteorite-list] Atmospheric ablation > marks on Tektites? > > > > Hi! > > > > Ok, now I figuring out this tektite issue. I want > > to thank ev
Re: [meteorite-list] ?????Monahans-1998????????
an old bolt, nut and some other old farming-stuff, new metal-detector and a lot of zeal. Living on a country-side, and can find same-kind of material from every older field, a black piece on the right may look worth of the closer check. Othesr are man-made and much too rusty to be from under 10 years old fall in a quite dry climate. Suppose, they have to wait for NASA another 10 years... just my 2 euro-cents ;- pekka s Pete Shugar kirjoitti: Someone want to check out Ebay auction # 310038556946 They claim just over 6 grams of Monahans 1998 starting at 0.99 and no bids so far. They don't look like any meteorite I've ever seen. Looks more like some old Roman or Greek coins. Pete __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list -- Solar Gems Pekka Savolainen Jokiharjuntie 4 FI-71330 Rasala FINLAND GSM + 358 400 818 912 [EMAIL PROTECTED] Member of IMCA 5776 www.imca.cc __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Auction at Bonhams on April 30 in New York.
This may be just a wild guess, but maybe Bonhams has the auction listed on their website since it is less than a month away. --- Timothy Heitz <[EMAIL PROTECTED]> wrote: > > > > Hello List, > > Does anyone know if any other meteorites are being > offered? > > > Tim Heitz > Midwest Meteorite - http://www.meteorman.org/ > > > > > > > > > > Go to Google News > Rare meteorite goes under hammer > 10 hours ago > > A meteorite is expected to fetch £500,000 at > auction in New York this > month. > > Weighing more than 925lbs, the object was > discovered eight years ago in > China's Xinjiang Uygar province. > > Its rare olivine crystals endured atmospheric and > impact forces as it > crashed down to Earth. > > Bonhams' Natural History Department director Thomas > Lindgren said: "Less > than 1% of all meteorites are pallasites, the most > alluring of all > meteorites due to their aesthetic appeal." > > Pallasites - meteorites composed of around 50% > olivine and peridot crystals > and 50% nickel-iron - are thought to be relics of > forming planets. > > The Fukang meteorite will go under the hammer at > Bonhams on April 30 in New > York. > > __ > http://www.meteoritecentral.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > Don Rawlings You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] ?????Monahans-1998????????
Looks to me more like the rusted remnants from a ranch, or an old blacksmith's shop. Some pieces look like pieces of an old horseshoe, or maybe some type of hand-wrought hardware like a latch or hinge. Note the nearly square or rectangular holes in some pieces. Not a stretch since this stuff was found in Texas. But that's just me. Ed - Original Message - From: "Pete Shugar" <[EMAIL PROTECTED]> To: Sent: Saturday, April 05, 2008 9:37 PM Subject: [meteorite-list] ?Monahans-1998 Someone want to check out Ebay auction # 310038556946 They claim just over 6 grams of Monahans 1998 starting at 0.99 and no bids so far. They don't look like any meteorite I've ever seen. Looks more like some old Roman or Greek coins. Pete __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] ?????Monahans-1998????????
Someone want to check out Ebay auction # 310038556946 They claim just over 6 grams of Monahans 1998 starting at 0.99 and no bids so far. They don't look like any meteorite I've ever seen. Looks more like some old Roman or Greek coins. Pete __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Auction at Bonhams on April 30 in New York.
Hello List, Does anyone know if any other meteorites are being offered? Tim Heitz Midwest Meteorite - http://www.meteorman.org/ Go to Google News Rare meteorite goes under hammer 10 hours ago A meteorite is expected to fetch £500,000 at auction in New York this month. Weighing more than 925lbs, the object was discovered eight years ago in China's Xinjiang Uygar province. Its rare olivine crystals endured atmospheric and impact forces as it crashed down to Earth. Bonhams' Natural History Department director Thomas Lindgren said: "Less than 1% of all meteorites are pallasites, the most alluring of all meteorites due to their aesthetic appeal." Pallasites - meteorites composed of around 50% olivine and peridot crystals and 50% nickel-iron - are thought to be relics of forming planets. The Fukang meteorite will go under the hammer at Bonhams on April 30 in New York. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] test
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Re: [meteorite-list] Fireball ???
Sonny, I for sure is worth a look, the worst that could happen is that you find nothing and get tired of walking around hunting. The best is that you find a new meteorite and make a little money and get a great new stone or two for your collection, just keep us updated on the hunt results. I want to wish you the best luck hunting, hope to see some photos of your new finds, you can post them on the SkyRock Cafe for us all to drool over. Best, Joe Kerchner http://illinoismeteorites.com http://skyrockcafe.com On Fri, Apr 4, 2008 at 10:14 PM, <[EMAIL PROTECTED]> wrote: > Hi All, > > I received a phone call today about a possible fireball. Two ranch hands > were riding back while herding cattle when they both saw what appeared to be > a red fireball with a silver tail hit into the side of a mountain not far > from their location. They also saw a large dust cloud that appeared after > impact. They were not able to ride to the area until the next day due to the > time of night and location on the hillside.The following day they went to > the area but were unable to find anything. I have been told that most > meteorites burnout before entering the atmosphere. What are the chances of > this being a meteorite ,or more likely be space junk? Would it be worth the > time to investigate? I will have more information tomorrow due to the phone > service in the area. > > > Sonny > > www.nevadameteorites.com > __ > http://www.meteoritecentral.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Doug, did I miss something? You are aware about what Sterling surmised about Carancas history from its composition? A rather unique history deduced from hands on observation. Considering such a violent past unique consequences are not impossible? Excuse me for jumping in here with both feet [perhaps to be deposited into mouth] but that's what I get for Skimming thru this thread. Jerry Flaherty - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Saturday, April 05, 2008 5:36 PM Subject: Re: [meteorite-list] New, long, Carancas article II Sterling W. wrote: "And by your next Post, you'd noticed the gigantic Fly in the Ointment when you asked: "Why don't other stony meteorites with TKW's over a ton do the same thing? In fact, there's a key word missing in that question: "Why don't ALL other stony meteorites with TKW's over a ton do the same thing?" Hi Sterling, Perhaps your basic assumption was right and we are seeing the start of the invasion of the Monolith Monsters. I'll check with Professor Flanders and see what he thinks... I could care less whether the Schultz idea is correct or not for Carancas - though all ideas need to be judged without bias to figure out the answer there. It is much more interesting IMO to think about what happens if a (semi)rubble-pile object entered the atmosphere. Rubble-pile is one asteroid model that is accepted, so this is a refreshingly new idea for me to yap about. And this brings to mind the really exciting possibility that some models of meteoric entry can be based on a liquidish and wave-like behavior of the bolide, rather than a solid behavior. That is a very bold assumption and will require Schultz and his supporters to get his act well choreographed. "In fact", there is no key word missing from my question. "Fact" is a different animal from debate, and I hope you can keep this straight. So to be more convincing kindly just give thanks when others are the inspiration for your arguments. On asking why we don't see this partial disintegration behavior on other large impactors, I requested (mulled) some info to further clarify this potential fatal flaw. However, the competing theories all have their problems at the moment. Schultz's theory seems to address the problem of fragmentation much better than an oriented stone that wasn't slowed down enough by the time it his 10-15km altitude to have a soft landing and not be shredded to bits as it smashed into the dense atmosphere at 3 km/s. I do disagree with the words you've put into Occam's mouth on two counts. First, you're decided that Occam's razor applies only positively to your scenario of carefully specifying dimensions of the incoming object, rather than just saying it fragments apart as current theory would usually expect. I wouldn't immediately conclude either is less complexity. The mass was found fragmented. How it got there is the challenge. If you pre-suppose it fragmented upon impact and you don't have evidence to back that up, you are on thin ice. Second, in breathing life into William Occam's postulate you are relying on an "authority" to keep the mind closed to the Schultz idea. There is no authority. You can quote a monk or even God, if you want to do faith-based science. Better, just stick to the evidence. Wild Bill actually told me he was on the fence regarding Carancas, too. I was very careful in my comments to say I am still on the fence regarding both the Schultz scenario as well as the basic oriented single car choo-choo train scenario. What I do appreciate from the Schultz contribution is the opportunity it gives for an open mind to contemplate what would happen with a dense particle stream entering or being created as a meteoroid. As for the set of curiosities I posted which this novel theory would make, I am glad you latched onto the first one to prove what you already knew already (for my benefit, thanks). I did not post that with any posterior revelation that there is a "Giant Fly in the Ointment". There is no key word missing in my post... I don't mean to come down harshly on the thought that a monolith could be the answer ... but respectfully I see you have manipulated Wild Bill Occam as well as my own statements in a way neither of us intended - I do need to reject your argument for rejecting the new theory on the block as more political than scientific. Best wishes and Great Health, Doug -Original Message- From: Sterling K. Webb <[EMAIL PROTECTED]> To: meteorite-list@meteoritecentral.com; [EMAIL PROTECTED] Sent: Sat, 5 Apr 2008 2:04 pm Subject: Re: [meteorite-list] New, long, Carancas article II Hi, Doug, to Schultz's credit, he has put a novel mechanism on the table... Not only a novel mechanism but an unnecessary one. This is just what Wild Bill Occam called "multiplying entities without necessity." And by your next Post, you'd noti
[meteorite-list] Chat tonite
Hello everyone. I am sorry about the short notice. But we are going to have a meteorite chat session at the skyrock cafe meteorite talk chat room. Here is a link to the chat room. http://illinoismeteorites.com/meteoritetalk/chat/ Again I am sorry about the short notice, but I was just informed about it myself. Hope to see(talk to) you all there. We are going to meet there at 9pm central time. that is about 1 hour from now. Best, Joe Kerchner __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Mount Tazerait, Is it obtainable?
So cool! Jerry Flaherty - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Saturday, April 05, 2008 11:49 AM Subject: [meteorite-list] Mount Tazerait, Is it obtainable? Hi List, I recently imaged a thin section of Mount Tazerait L5. I found it fell Aug 21 1991 in Niger but I haven't seen any for sale (since I started looking which was just recently). Is this a hard one to find? In the thin section was a large inclusion. I have many cool micrographs of it on the March Meteorite Times issue (Open the magazine and click on Micro Visions). http://www.meteorite-times.com/meteorite_frame.htm This inclusion was different from what I am used to seeing and reminded me of some Earth like volcanic structures. I won't start tossing descriptive names around because I might be way off. Any of you with the time and inclination, please share your thoughts of what this stuff reminds you of. And if any one knows of Mount T for sale, please let me know. Thanks, Tom Phillips **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD: (sort of) My Free Meteorite Micrograph Screen Saver Download
Hi list, Paul (Meteorite Times) has set up a page on the Meteorite Exchange site where you can view the images from the new cross polarized light meteorite micrograph screen saver and download it for free. http://www.meteorite.com/meteorite-gallery/screensaver/ It is a great page and I really appreciate all the hard work Paul has put into my shots! Thanks Paul! Also, I have had some interesting observations about the Mount Tazerait inclusion micrographs (and by the way, Anne Black has some Mount T for sale on her site http://www.impactika.com/Metlist.htm ) I did get a question about how to find the shots. Go to the Meteorite Times Magazine http://www.meteorite-times.com/meteorite_frame.htm and the in the top left there is a section called "Columns", in that section is the button for my "Micro Visions" A few people went to the Tom Phillips Gallery and could not find "Micro Vision" in the Gallery. If you have not seen those shots, PLEASE TAKE A LOOK! And let us know what you think. Thanks, Tom **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Find a Falling Star
On Sat, 05 Apr 2008 19:03:21 -0400, you wrote: >Hi Walter, > >Edwin Thompson (ET) has several copies of both versions in great >condition and at friendly prices. I got one from him in February and >really appreciated his dealing with me. Interesting things happening with the price of Find a Falling Star right now: http://www.amazon.com/gp/offer-listing/083972229X http://www.amazon.com/gp/offer-listing/B000HQ8EZU http://www.fetchbook.info/find_a_falling_star.html I bought my paperback copy almost exactly 3 years ago-- April 10th 2005, for $19.99 BIN on Ebay from-- Walter Branch. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Hi, Doug, 1. It is a fact that all one-ton-plus stones do not behave this way. It is a fact that very few one-ton-plus stones do. > just give thanks when others are the > inspiration for your arguments 2. I owe no inspiration to Schultz. I proposed my present analysis on the List in October 2007, about four months before first intimation of the Schultz paper-to-be-published. He has one story that arrives at an elongated object. I had another story that goes to the same place. 3. There is no "train" of debris in the Schultz Model. Such a thing is impossible. The stuff at the front is retarted more than the stuff behind it. The stuff in the back is crammed up against the tardy front. It's self-compactiug. If you read Schultz's LPI paper, he says "the pancake model fails," meaning why doesn't this effect spread the debris out over an ever-broadening front, a catastrophic sequence that leads to airburst? He offers no answer other than to say that if he twiddles with the aerodynamic model he thinks maybe he can make it happen in the computer. (If he had a conclusive demonstration, he would have presented it. Also means he's been trying and can't do it yet.) 4. I will leave Wild Bill Occam out of all future discussions. Fact is, he's over to the saloon, drunk on his Franciscan keister, having discovered the advances in distillation that have happened since the 14th century... He's no longer available. Sterling K. Webb - - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Saturday, April 05, 2008 4:36 PM Subject: Re: [meteorite-list] New, long, Carancas article II Sterling W. wrote: "And by your next Post, you'd noticed the gigantic Fly in the Ointment when you asked: "Why don't other stony meteorites with TKW's over a ton do the same thing? In fact, there's a key word missing in that question: "Why don't ALL other stony meteorites with TKW's over a ton do the same thing?" Hi Sterling, Perhaps your basic assumption was right and we are seeing the start of the invasion of the Monolith Monsters. I'll check with Professor Flanders and see what he thinks... I could care less whether the Schultz idea is correct or not for Carancas - though all ideas need to be judged without bias to figure out the answer there. It is much more interesting IMO to think about what happens if a (semi)rubble-pile object entered the atmosphere. Rubble-pile is one asteroid model that is accepted, so this is a refreshingly new idea for me to yap about. And this brings to mind the really exciting possibility that some models of meteoric entry can be based on a liquidish and wave-like behavior of the bolide, rather than a solid behavior. That is a very bold assumption and will require Schultz and his supporters to get his act well choreographed. "In fact", there is no key word missing from my question. "Fact" is a different animal from debate, and I hope you can keep this straight. So to be more convincing kindly just give thanks when others are the inspiration for your arguments. On asking why we don't see this partial disintegration behavior on other large impactors, I requested (mulled) some info to further clarify this potential fatal flaw. However, the competing theories all have their problems at the moment. Schultz's theory seems to address the problem of fragmentation much better than an oriented stone that wasn't slowed down enough by the time it his 10-15km altitude to have a soft landing and not be shredded to bits as it smashed into the dense atmosphere at 3 km/s. I do disagree with the words you've put into Occam's mouth on two counts. First, you're decided that Occam's razor applies only positively to your scenario of carefully specifying dimensions of the incoming object, rather than just saying it fragments apart as current theory would usually expect. I wouldn't immediately conclude either is less complexity. The mass was found fragmented. How it got there is the challenge. If you pre-suppose it fragmented upon impact and you don't have evidence to back that up, you are on thin ice. Second, in breathing life into William Occam's postulate you are relying on an "authority" to keep the mind closed to the Schultz idea. There is no authority. You can quote a monk or even God, if you want to do faith-based science. Better, just stick to the evidence. Wild Bill actually told me he was on the fence regarding Carancas, too. I was very careful in my comments to say I am still on the fence regarding both the Schultz scenario as well as the basic oriented single car choo-choo train scenario. What I do appreciate from the Schultz contribution is the opportunity it gives for an open mind to contemplate what would happen with a dense particle stream entering or being created as a meteoroid. As for the set of curiosities I posted which this n
Re: [meteorite-list] Australite Tektites
James Tobin wrote: Hi List, Thank you Michael B for the kind words about my thin sections of buttons. That was a long time ago. There is a micrograph of a picture of one of those I still have in the September 2003 issue of Meteorite Times. If you go to the current issue and use the link to back issues which is near the top of the page under the rotation banner ads at the top center select article and choose Tektite of the Month. Here is a list of other articles with great pictures of buttons from Tektite of the Month. Sorry I don't have time right now to copy all these links into this message. June 2007, May 2007, December 2006, February 2005, October 2004, and the one mentioned above with the thin section picture September 2003. http://www.meteorite-times.com/Back_Links/2003/September/Tektite_of_Month.htm http://www.meteorite-times.com/Back_Links/2004/October/Tektite_of_Month.htm http://www.meteorite-times.com/Back_Links/2005/February/Tektite_of_Month.htm http://www.meteorite-times.com/Back_Links/2006/December/Tektite_of_Month.htm http://www.meteorite-times.com/Back_Links/2007/May/Tektite_of_Month.htm http://www.meteorite-times.com/Back_Links/2007/June/Tektite_of_Month.htm The button type tektites would appear to be cold solid bodies that return from near space at velocities high enough to ablate and the forward surface melts. The liquid glass rolls up like a jelly roll often not welding well or at all to the shrinking core body of the tektite. Often the stresses are so great that the whole front of the tektite called appropriately enough the "aerodynamic stress shield" will detach. The reasons for this are debated still. I personally lean somewhat to a thermal shock of somekind between the cold core and the heated outside. But would not get into a fight over this, there may be a better reason for this detachment of the forward ringwave surface and flange. The fact that many are found with adhering pieces of ringwave and flange would seem to support that internal fracturing happens. The flat surfaces characteristically seen on cores of ablated tektites would indicate to me that fracturing happens as well. If ablation continues long enough the rolled back material and the unwelded narrow valley which forms next to the cold core will proceed to such a degree that the bottom of the valley will actually reach the front surface that is ablating and the ring itself can detach. Very rarely these rings have been found unbroken as separate specimens. I have personally only held one complete detached ring. But holding that one was exciting. The ringwaves are a property that they receive from a combination of their spin the motion of the liquid material that is rolling up and the air currents against the face as it slows down and cools. Sometime this intricate pattern will be very waffley if the flange itself is thin enough. The ring waves are one of my favorite aspects of ablated tektites. I will return to lurking. Best regards, Jim __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Australite Tektites
Hi List, Thank you Michael B for the kind words about my thin sections of buttons. That was a long time ago. There is a micrograph of a picture of one of those I still have in the September 2003 issue of Meteorite Times. If you go to the current issue and use the link to back issues which is near the top of the page under the rotation banner ads at the top center select article and choose Tektite of the Month. Here is a list of other articles with great pictures of buttons from Tektite of the Month. Sorry I don't have time right now to copy all these links into this message. June 2007, May 2007, December 2006, February 2005, October 2004, and the one mentioned above with the thin section picture September 2003. The button type tektites would appear to be cold solid bodies that return from near space at velocities high enough to ablate and the forward surface melts. The liquid glass rolls up like a jelly roll often not welding well or at all to the shrinking core body of the tektite. Often the stresses are so great that the whole front of the tektite called appropriately enough the "aerodynamic stress shield" will detach. The reasons for this are debated still. I personally lean somewhat to a thermal shock of somekind between the cold core and the heated outside. But would not get into a fight over this, there may be a better reason for this detachment of the forward ringwave surface and flange. The fact that many are found with adhering pieces of ringwave and flange would seem to support that internal fracturing happens. The flat surfaces characteristically seen on cores of ablated tektites would indicate to me that fracturing happens as well. If ablation continues long enough the rolled back material and the unwelded narrow valley which forms next to the cold core will proceed to such a degree that the bottom of the valley will actually reach the front surface that is ablating and the ring itself can detach. Very rarely these rings have been found unbroken as separate specimens. I have personally only held one complete detached ring. But holding that one was exciting. The ringwaves are a property that they receive from a combination of their spin the motion of the liquid material that is rolling up and the air currents against the face as it slows down and cools. Sometime this intricate pattern will be very waffley if the flange itself is thin enough. The ring waves are one of my favorite aspects of ablated tektites. I will return to lurking. Best regards, Jim __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Find a Falling Star
Hi Walter, Edwin Thompson (ET) has several copies of both versions in great condition and at friendly prices. I got one from him in February and really appreciated his dealing with me. Best wishes and Great Health, Doug -Original Message- From: Walter Branch <[EMAIL PROTECTED]> To: Meteorite List Sent: Sat, 5 Apr 2008 4:47 pm Subject: [meteorite-list] Find a Falling Star Hello Everyone, Does anyone have a copy of Nininger's Find a Falling Star for sale? Preferably the softcover version. Thanks. -Walter Branch __ http://www.meteoritecentral.com Meteorite-list mailing list [EMAIL PROTECTED] http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Find a Falling Star
Hello Everyone, Does anyone have a copy of Nininger's Find a Falling Star for sale? Preferably the softcover version. Thanks. -Walter Branch __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteorite Coin Collection and scope
> Wow Don! I am officially JEALOUS of that collection! Congrats, Don! Very nice (and complete) metcoin collection! Cheers, Bernd (who collects Australian Kookaburra silver coins) > (nice scope too!) Yep, nice Newtonian!!! Bernd __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteorite Coin Collection
Wow Don! I am officially JEALOUS of that collection! (nice scope too!) :) Regards, MikeG -- Hi List. Just wanted to excitedly say that after 4 years of searching I finally purchased the "Holy Grail" of Meteorite Coins and the only one missing from my collection and that is the 2004 Liberia "NWA 267 Meteorite" coin!! It's huge! Especially compared to the other Silver 2006 and 2007 coins. I was very lucky price wise too, since this has sold now from anywhere's in the $300-$500 range. For those that want a look, just click on the site below to view my Meteorite Collection pics. The "NWA 267 Meteorite" Coin are the first 3 pics at the top of page. Just click on a pic that you want to see closer up. Just wanted to share the good news is all. Here is the site. http://s212.photobucket.com/albums/cc276/emflocater/ Sincerely Don Merchant IMCA #0960 You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] AD-Special: Premiere of a New Martian: - NWA 4925 - Olivine-orthopyroxene-phyric Shergottite
Thank you! We're indeed very happy about it - such stones show us, that the sometimes really laborious work is well worth it, isn't it? Maybe the recent fireball over France, Suisse, Southern Germany produced a Martian? Would be more comfort for us... But so far nothing found :-( -Ursprüngliche Nachricht- Von: Michael Farmer [mailto:[EMAIL PROTECTED] Gesendet: Sonntag, 6. April 2008 00:03 An: Martin Altmann; Meteorite-list@meteoritecentral.com Betreff: Re: [meteorite-list] AD-Special: Premiere of a New Martian: - NWA 4925 - Olivine-orthopyroxene-phyric Shergottite Wonderful new Martian meteorite Martin! It has been a while since a nice new Mars rock hit the market. I am still waiting for a large Martian meteorite fall, that will be a dream come true if that happens. Mike --- Martin Altmann <[EMAIL PROTECTED]> wrote: > Dear Collectors, > > The presentation of a new Martian meteorite to the > meteorite community is > always an event. > Such introductions of new lunaites and Martians are > those moments that are > most fulfilling in the life and work of a > meteorite-addicted person. > And we hope that you will share at least partially > our exaltation about this > new fabulous stone, named > > NWA 4925 > Purchased 2007, > Morocco > Tkw 282.3g > o-SHE > > Understandably, we aren't really unbiased regarding > our new Mars rock, and > so we asked one of the best and most experienced > connoisseurs of Martian > meteorites, Norbert Classen, known also to be the > author of one of the best > homepages for lunar and Martian meteorites > (http://www.meteoris.de/) for his > opinion on NWA 4295, and we are much obliged that he > allowed us to report > his observations and his opinions about the new > material: > > "Right now we know about 50 different, i.e. unpaired > Martian meteorites, > including 4 witnessed falls (Chassigny, Shergotty, > Nakhla, and Zagami), 15 > Antarctic finds, and 31 hot desert finds, most of > them having been recovered > from the deserts of Africa. The majority of all > Martian meteorites belongs > to the class of mostly "enriched" basaltic > shergottites, while the > "depleted" group of olivine-phyric, and > olivine-orthopyroxene-phyric > shergottites are far less abundant. NWA 4925 belongs > to the latter subgroup > which consists of just about 5 different members, > including the Dar al Gani > shergottites, NWA 1195, NWA 2626, NWA 2046, and NWA > 4527 (TKW 10g). NWA 4925 > is possibly paired with the latter one, but up to > this moment no studies > have been conducted to prove or disprove this > suspicion that's only based on > a comparison of overall texture, and weathering > grade. > > Like NWA 1195 and NWA 4527, the new NWA 4925 > exhibits a pronounced light > colored weathering rind, typical for desert finds > with long terrestrial > residence ages. Olivine phenocrysts near to or > within the weathering rind do > often show a bright red appearance, a sign that most > of the iron within > these olivines has been oxidized in the terrestrial > environment. Overall, > the matrix color within or near to the rind is more > redish - reminding us of > the same process that gives Mars its red appearance > although most of the > Martian rocks are originally of grey, or grey to > green color. The interior > of NWA 4925 is actually dark green, with shock > altered dark-brown olivine > phenocrysts set in a matrix of more fine grained > greenish pyroxenes and dark > maskelynite, both bearing witness for the fact that > the interior of the rock > is more or less pristine and fresh, just as if it > left Mars only yesterday. > It's that interesting contrast of the more > light-colored weathering rind > with its neat redish olivines, and the dark-green, > very fresh interior that > makes NWA 4925 visually most attractive, and > scientifically interesting > because it models the surface weathering on the Red > Planet. > > >From the samples of NWA 4925 that I could study I > would further suspect that > the olivine and orthopyroxene phenocrysts show a > preferred orientation like > in NWA 1195, and other ol-opx-phyric shergottites, > something which is > indicative of magmatic flow prior to the cooling and > solidification of the > sample. Other most interesting features are melt > inclusions, and small > chromites that are enclosed into the large olivine > phenocrysts. Overall, a > very interesting, and optically most attractive new > Martian meteorite of a > rare class. A "must have" for any serious collector > of planetary meteorites, > and rare achondrites." > > > Dear collectors, > For us the acquisition of this new Martian was > combined with various > difficulties and we are glad and happy to have it > finally in our very hands. > Therefore we simply decided against all advice and > economical reason to > share our joy and to choose for this introductory & > exclusive special > > a price of 400$ per gram! > > We hope for your understanding, that this offer will > be
[meteorite-list] AD - Huge Oriented Meteorite
Hello List, Please have a look at my oriented meteorite just listed on ebay. http://cgi.ebay.com/Huge-Oriented-Sheild-Meteorite-over-8-LBS_W0QQitemZ250233779073QQihZ015QQcategoryZ3239QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Have a great weekend ! Thanks, Bob __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD-Special: Premiere of a New Martian: - NWA 4925 - Olivine-orthopyroxene-phyric Shergottite
Dear Collectors, The presentation of a new Martian meteorite to the meteorite community is always an event. Such introductions of new lunaites and Martians are those moments that are most fulfilling in the life and work of a meteorite-addicted person. And we hope that you will share at least partially our exaltation about this new fabulous stone, named NWA 4925 Purchased 2007, Morocco Tkw 282.3g o-SHE Understandably, we aren't really unbiased regarding our new Mars rock, and so we asked one of the best and most experienced connoisseurs of Martian meteorites, Norbert Classen, known also to be the author of one of the best homepages for lunar and Martian meteorites (http://www.meteoris.de/) for his opinion on NWA 4295, and we are much obliged that he allowed us to report his observations and his opinions about the new material: "Right now we know about 50 different, i.e. unpaired Martian meteorites, including 4 witnessed falls (Chassigny, Shergotty, Nakhla, and Zagami), 15 Antarctic finds, and 31 hot desert finds, most of them having been recovered from the deserts of Africa. The majority of all Martian meteorites belongs to the class of mostly "enriched" basaltic shergottites, while the "depleted" group of olivine-phyric, and olivine-orthopyroxene-phyric shergottites are far less abundant. NWA 4925 belongs to the latter subgroup which consists of just about 5 different members, including the Dar al Gani shergottites, NWA 1195, NWA 2626, NWA 2046, and NWA 4527 (TKW 10g). NWA 4925 is possibly paired with the latter one, but up to this moment no studies have been conducted to prove or disprove this suspicion that's only based on a comparison of overall texture, and weathering grade. Like NWA 1195 and NWA 4527, the new NWA 4925 exhibits a pronounced light colored weathering rind, typical for desert finds with long terrestrial residence ages. Olivine phenocrysts near to or within the weathering rind do often show a bright red appearance, a sign that most of the iron within these olivines has been oxidized in the terrestrial environment. Overall, the matrix color within or near to the rind is more redish - reminding us of the same process that gives Mars its red appearance although most of the Martian rocks are originally of grey, or grey to green color. The interior of NWA 4925 is actually dark green, with shock altered dark-brown olivine phenocrysts set in a matrix of more fine grained greenish pyroxenes and dark maskelynite, both bearing witness for the fact that the interior of the rock is more or less pristine and fresh, just as if it left Mars only yesterday. It's that interesting contrast of the more light-colored weathering rind with its neat redish olivines, and the dark-green, very fresh interior that makes NWA 4925 visually most attractive, and scientifically interesting because it models the surface weathering on the Red Planet. >From the samples of NWA 4925 that I could study I would further suspect that the olivine and orthopyroxene phenocrysts show a preferred orientation like in NWA 1195, and other ol-opx-phyric shergottites, something which is indicative of magmatic flow prior to the cooling and solidification of the sample. Other most interesting features are melt inclusions, and small chromites that are enclosed into the large olivine phenocrysts. Overall, a very interesting, and optically most attractive new Martian meteorite of a rare class. A "must have" for any serious collector of planetary meteorites, and rare achondrites." Dear collectors, For us the acquisition of this new Martian was combined with various difficulties and we are glad and happy to have it finally in our very hands. Therefore we simply decided against all advice and economical reason to share our joy and to choose for this introductory & exclusive special a price of 400$ per gram! We hope for your understanding, that this offer will be limited for the pieces pictured on the special-page and for all other orders too (in case the special-specimens will be sold out) until Sunday next week; and that afterwards we will have to adjust the price to the more general Martian price-level. And here is the beef: http://www.chladnis-heirs.com/special-nwa4925.html Enjoy! Martin & Stefan Chladni's Heirs Munich - Berlin Fine Meteorites for Science&Collectors __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Sterling W. wrote: "And by your next Post, you'd noticed the gigantic Fly in the Ointment when you asked: "Why don't other stony meteorites with TKW's over a ton do the same thing? In fact, there's a key word missing in that question: "Why don't ALL other stony meteorites with TKW's over a ton do the same thing?" Hi Sterling, Perhaps your basic assumption was right and we are seeing the start of the invasion of the Monolith Monsters. I'll check with Professor Flanders and see what he thinks... I could care less whether the Schultz idea is correct or not for Carancas - though all ideas need to be judged without bias to figure out the answer there. It is much more interesting IMO to think about what happens if a (semi)rubble-pile object entered the atmosphere. Rubble-pile is one asteroid model that is accepted, so this is a refreshingly new idea for me to yap about. And this brings to mind the really exciting possibility that some models of meteoric entry can be based on a liquidish and wave-like behavior of the bolide, rather than a solid behavior. That is a very bold assumption and will require Schultz and his supporters to get his act well choreographed. "In fact", there is no key word missing from my question. "Fact" is a different animal from debate, and I hope you can keep this straight. So to be more convincing kindly just give thanks when others are the inspiration for your arguments. On asking why we don't see this partial disintegration behavior on other large impactors, I requested (mulled) some info to further clarify this potential fatal flaw. However, the competing theories all have their problems at the moment. Schultz's theory seems to address the problem of fragmentation much better than an oriented stone that wasn't slowed down enough by the time it his 10-15km altitude to have a soft landing and not be shredded to bits as it smashed into the dense atmosphere at 3 km/s. I do disagree with the words you've put into Occam's mouth on two counts. First, you're decided that Occam's razor applies only positively to your scenario of carefully specifying dimensions of the incoming object, rather than just saying it fragments apart as current theory would usually expect. I wouldn't immediately conclude either is less complexity. The mass was found fragmented. How it got there is the challenge. If you pre-suppose it fragmented upon impact and you don't have evidence to back that up, you are on thin ice. Second, in breathing life into William Occam's postulate you are relying on an "authority" to keep the mind closed to the Schultz idea. There is no authority. You can quote a monk or even God, if you want to do faith-based science. Better, just stick to the evidence. Wild Bill actually told me he was on the fence regarding Carancas, too. I was very careful in my comments to say I am still on the fence regarding both the Schultz scenario as well as the basic oriented single car choo-choo train scenario. What I do appreciate from the Schultz contribution is the opportunity it gives for an open mind to contemplate what would happen with a dense particle stream entering or being created as a meteoroid. As for the set of curiosities I posted which this novel theory would make, I am glad you latched onto the first one to prove what you already knew already (for my benefit, thanks). I did not post that with any posterior revelation that there is a "Giant Fly in the Ointment". There is no key word missing in my post... I don't mean to come down harshly on the thought that a monolith could be the answer ... but respectfully I see you have manipulated Wild Bill Occam as well as my own statements in a way neither of us intended - I do need to reject your argument for rejecting the new theory on the block as more political than scientific. Best wishes and Great Health, Doug -Original Message- From: Sterling K. Webb <[EMAIL PROTECTED]> To: meteorite-list@meteoritecentral.com; [EMAIL PROTECTED] Sent: Sat, 5 Apr 2008 2:04 pm Subject: Re: [meteorite-list] New, long, Carancas article II Hi, Doug, to Schultz's credit, he has put a novel mechanism on the table... Not only a novel mechanism but an unnecessary one. This is just what Wild Bill Occam called "multiplying entities without necessity." And by your next Post, you'd noticed the gigantic Fly in the Ointment when you asked: "Why don't other stony meteorites with TKW's over a ton do the same thing?" In fact, there's a key word missing in that question: "Why don't ALL other stony meteorites with TKW's over a ton do the same thing?" [Scribble, scribble...] If they all did, we would have a Carancas-crater event roughly every three weeks. (That's 170 fresh 10-meter craters since 1998.) Sterling K. Webb -- - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Saturday, April
[meteorite-list] Finally after 4 years I have it!!
Hi List. Just wanted to excitedly say that after 4 years of searching I finally purchased the "Holy Grail" of Meteorite Coins and the only one missing from my collection and that is the 2004 Liberia "NWA 267 Meteorite" coin!! It's huge! Especially compared to the other Silver 2006 and 2007 coins. I was very lucky price wise too, since this has sold now from anywhere's in the $300-$500 range. For those that want a look, just click on the site below to view my Meteorite Collection pics. The "NWA 267 Meteorite" Coin are the first 3 pics at the top of page. Just click on a pic that you want to see closer up. Just wanted to share the good news is all. Here is the site. http://s212.photobucket.com/albums/cc276/emflocater/ Sincerely Don Merchant IMCA #0960 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Drop that Fukang hammer!
http://ukpress.google.com/article/ALeqM5gU1vRUl9uzvx16sYWx8uzgK7wemQ Rare meteorite goes under hammer 10 hours ago A meteorite is expected to fetch £500,000 at auction in New York this month. Weighing more than 925lbs, the object was discovered eight years ago in China's Xinjiang Uygar province. Its rare olivine crystals endured atmospheric and impact forces as it crashed down to Earth. Bonhams' Natural History Department director Thomas Lindgren said: "Less than 1% of all meteorites are pallasites, the most alluring of all meteorites due to their aesthetic appeal." Pallasites - meteorites composed of around 50% olivine and peridot crystals and 50% nickel-iron - are thought to be relics of forming planets. The Fukang meteorite will go under the hammer at Bonhams on April 30 in New York. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Hi, Doug, > to Schultz's credit, he has put > a novel mechanism on the table... Not only a novel mechanism but an unnecessary one. This is just what Wild Bill Occam called "multiplying entities without necessity." And by your next Post, you'd noticed the gigantic Fly in the Ointment when you asked: > "Why don't other stony meteorites with > TKW's over a ton do the same thing?" In fact, there's a key word missing in that question: "Why don't ALL other stony meteorites with TKW's over a ton do the same thing?" [Scribble, scribble...] If they all did, we would have a Carancas-crater event roughly every three weeks. (That's 170 fresh 10-meter craters since 1998.) Sterling K. Webb -- - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Saturday, April 05, 2008 11:26 AM Subject: Re: [meteorite-list] New, long, Carancas article II Sterling W. wrote: "Both Schultz and I calculate that the object was still supersonic when it hit, still enclosed in a "detached" shock wave, so the sides never ablated at any point." Hi Sterling, Yes, but to Schultz's credit, he has put a novel mechanism on the table for scientific consideration of these "strange" dynamics and motivated the issue of the role of the shock wave IMO to begin with. The oriented case as presented by you and many others at that time was an extrapolation IMO. I personally like Schultz' refreshing contribution in the field. I would rather call your thoughts the natural control for Schultz' idea, and not anything particularly novel in meteoritical circles. While any idea will need to be earthshattering :-), which explanation (the basic made into a very special case or the spontaneous reorganization and its complexity - or csome combination of ideas) at this point best complies with Occam's Razor is not obvious to me. However, no matter how distorted in length vs. width, if we consider the object was over a ton, that is still a real lot of surface area to survive down to a relatively very thick atmosphere at 4 km above sea level at that speed. I don't think the shock wave could have powered any deflector shields at the front of the bus - but I'm not qualitfied at the moment to comment on that. The shear experienced by the material at the front had to be enormous in the last 5-10 kilometers. So this Schultz theory sounds good and a welcomed addition to consideration vs. the highly oriented case. Sterling - do you or does anyone know if the shock veins have been shown by the scientists to have been caused upon impact with Earth? Best wishes and Great Health, Doug __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Tektite Buttons
Hi Mike and all, Jim Tobin did some great work on Australite buttons, making Modified "thin sections" from a cross section of a button that clearly Showed the ring forming from ablation and curling around the edge. I first saw these many years ago and bought one of the slides, Thinking it was one of the coolest things I had seen. I believe he Published a report on this within the last 2 years - eather in METEORITE TIMES or on METEORITE Magazine. Perhaps one of the list members (or Jim, if he is reading this) could tell the list what issue of which one. Best wishes, Michael on 4/5/08 8:07 AM, Michael Gilmer at [EMAIL PROTECTED] wrote: > this does not reasonably > explain > the appearance of "button" tektites of the > Australite variety. Although I must admit, the first > time I saw a button-type tektite, my first thought > was not atmospheric-ablation or sculpting. My first > thought was a splatter-type impact artifact. If you > have ever taken a spoonfull of viscous batter and > dropped it on the floor, the outer edges of the mass > will spread outward while the central area is uplifted > somewhat. I had erringly assumed that similar > physics were at work with the button-types. Perhaps > a massive detonation on impact liquified a combination > of meteorite and earthly-minerals which were blasted > upwards and then fell back to earth - forming into a > button when the material hit the ground again. 'Your living is determined not so much by what life brings to you as by the attitude you bring to life; not so much by what happens to you as by the way your mind looks at what happens.' --Kahlil Gibran __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Fwd: New, long, Carancas article II
Hi Friends and Listees, Just a few more comments on why this Schultz theory is refreshing IMO, as crazy as it initially sounded: If this mechanism is a valid one for larger objects, it raises the following curiosities: 1. Why don't other stony meteorites with TKW's over a ton do the same thing. 2. How many fair comparisons do we have in recorded meteoritidum that are comparable, e.g. non-carbonaceous big falls which are slowed by the atmosphere. 3. If this is a valid posibility, are our thought about "destroying" killer asteroids by fragmenting them in even hotter water? e.g., what if 10% of the fragments, to pick any fraction for argument's sake, exhibit this behavior. We can't count on the atmosphere to be the guardian angel for all pieces! 4. What happens to the fragmented material at the front of the enveloped train of hurdling debris? Does it fragment and basically vaporize (get smoked) and in so doing, open up a path for what's behind? 5. And if some pieces at the front survive, the friction will slow them down - then BOOM collision with those behind - and could we have an cyclical relay team progression of renewal of momentum at the head of the train maintaining the overall velocity? 6. If this "rely team" mechanism is maintained by a long and massive particle stream behind, is this effect possible: The actual shear at the front is lowered substantially for the overall velocity, basically using a sacrificial leading edge as a re-entry heat shield. Not agreeing with the mechanism - nor disagreeing, just brainstorming a bit. No doubt this was really smoking, does the energy disippated into making the smoke serve as a shield - amazing concept... Best wishes and Great Health, Doug -Original Message- From: [EMAIL PROTECTED] To: meteorite-list@meteoritecentral.com Sent: Sat, 5 Apr 2008 10:26 am Subject: Re: [meteorite-list] New, long, Carancas article II Sterling W. wrote: "Both Schultz and I calculate that the object was still supersonic when it hit, still enclosed in a "detached" shock wave, so the sides never ablated at any point." Hi Sterling, Yes, but to Schultz's credit, he has put a novel mechanism on the table for scientific consideration of these "strange" dynamics and motivated the issue of the role of the shock wave IMO to begin with. The oriented case as presented by you and many others at that time was an extrapolation IMO. I personally like Schultz' refreshing contribution in the field. I would rather call your thoughts the natural control for Schultz' idea, and not anything particularly novel in meteoritical circles. While any idea will need to be earthshattering :-), which explanation (the basic made into a very special case or the spontaneous reorganization and its complexity - or csome combination of ideas) at this point best complies with Occam's Razor is not obvious to me. However, no matter how distorted in length vs. width, if we consider the object was over a ton, that is still a real lot of surface area to survive down to a relatively very thick atmosphere at 4 km above sea level at that speed. I don't think the shock wave could have powered any deflector shields at the front of the bus - but I'm not qualitfied at the moment to comment on that. The shear experienced by the material at the front had to be enormous in the last 5-10 kilometers. So this Schultz theory sounds good and a welcomed addition to consideration vs. the highly oriented case. Sterling - do you or does anyone know if the shock veins have been shown by the scientists to have been caused upon impact with Earth? Best wishes and Great Health, Doug -Original Message- From: Sterling K. Webb <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Cc: meteorite-list@meteoritecentral.com; [EMAIL PROTECTED] Sent: Sat, 5 Apr 2008 1:23 am Subject: Re: [meteorite-list] New, long, Carancas article II Hi, In this context "contained" means contained by the back pressure envelope of the shock wave. The meteoric material would be far enough away from the shock not be heated very much. The shock wave at the sides is the hot stuff from the front and it's cooling down rapidly. Even in the entry of a spherical object the back side is not ablated. The melted rock on the back is running fluid from the front, not backside material that melted. And there's many a fine crusty meteorite whose back side is hardly touched by melt even though it's only a few inches away from the fire of re-entry. The shock wave is the boundary between material moving faster than sound (traveling with the meteoroid) and material not moving faster than sound (the surrounding atmosphere). Check the Wikipedia entry (very good discussion): http://en.wikipedia.org/wiki/Shock_wave "Shock waves are characterized by an abrupt, nearly discontinuous change in the characteristics of the medium. Across a shock there is always an extremely r
Re: [meteorite-list] Mount Tazerait, Is it obtainable?
Tom, List, Coincidentally, I had my slice of Mt. Taz out and under the microscope a couple weeks ago and I found a crystal in one of the vugs that was unlike ones I've seen in the past. I was surprised to find it because I thought I had looked in every vesicle on the specimen. Seems there is always a surprise inside when I break out my Taz! It's worth a look for sure if you are interested in these kinds of things. I can tell you that I've never before seen, nor would I expect to see a crystal like this in a meteorite. Those interested can email me off list and I'll send the image. Regards, Larry In a message dated 4/5/2008 10:49:55 A.M. Eastern Standard Time, [EMAIL PROTECTED] writes: Hi List, I recently imaged a thin section of Mount Tazerait L5. I found it fell Aug 21 1991 in Niger but I haven't seen any for sale (since I started looking which was just recently). Is this a hard one to find? In the thin section was a large inclusion.I have many cool micrographs of it on the March Meteorite Times issue (Open the magazine and click on Micro Visions). http://www.meteorite-times.com/meteorite_frame.htm This inclusion was different from what I am used to seeing and reminded me of some Earth like volcanic structures. I won't start tossing descriptive names around because I might be way off. Any of you with the time and inclination, please share your thoughts of what this stuff reminds you of. And if any one knows of Mount T for sale, please let me know. Thanks, Tom Phillips **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Sacramento Wash005 ( Franconia iron)
Hello List i am looking for photos of a etched Sacramento Wash005(Franconia)iron. I am interested to see how looks a etched iron from this found. The most found pieces are very small. But maybe someone has a larger piece etched? Can someone help me? many thanks Mirko IMCA#2113 www.meteorite-mirko.de Lesen Sie Ihre E-Mails jetzt einfach von unterwegs. www.yahoo.de/go __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Mount Tazerait, Is it obtainable?
In a message dated 4/5/2008 10:49:55 A.M. Eastern Standard Time, [EMAIL PROTECTED] writes: Hi List, I recently imaged a thin section of Mount Tazerait L5. I found it fell Aug 21 1991 in Niger but I haven't seen any for sale (since I started looking which was just recently). Is this a hard one to find? In the thin section was a large inclusion. I have many cool micrographs of it on the March Meteorite Times issue (Open the magazine and click on Micro Visions). http://www.meteorite-times.com/meteorite_frame.htm This inclusion was different from what I am used to seeing and reminded me of some Earth like volcanic structures. I won't start tossing descriptive names around because I might be way off. Any of you with the time and inclination, please share your thoughts of what this stuff reminds you of. And if any one knows of Mount T for sale, please let me know. Thanks, Tom Phillips **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list Tom, Try Anne Black. I bought a beautiful slice from her a few years ago. I think she still has plenty. Larry **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Sterling W. wrote: "Both Schultz and I calculate that the object was still supersonic when it hit, still enclosed in a "detached" shock wave, so the sides never ablated at any point." Hi Sterling, Yes, but to Schultz's credit, he has put a novel mechanism on the table for scientific consideration of these "strange" dynamics and motivated the issue of the role of the shock wave IMO to begin with. The oriented case as presented by you and many others at that time was an extrapolation IMO. I personally like Schultz' refreshing contribution in the field. I would rather call your thoughts the natural control for Schultz' idea, and not anything particularly novel in meteoritical circles. While any idea will need to be earthshattering :-), which explanation (the basic made into a very special case or the spontaneous reorganization and its complexity - or csome combination of ideas) at this point best complies with Occam's Razor is not obvious to me. However, no matter how distorted in length vs. width, if we consider the object was over a ton, that is still a real lot of surface area to survive down to a relatively very thick atmosphere at 4 km above sea level at that speed. I don't think the shock wave could have powered any deflector shields at the front of the bus - but I'm not qualitfied at the moment to comment on that. The shear experienced by the material at the front had to be enormous in the last 5-10 kilometers. So this Schultz theory sounds good and a welcomed addition to consideration vs. the highly oriented case. Sterling - do you or does anyone know if the shock veins have been shown by the scientists to have been caused upon impact with Earth? Best wishes and Great Health, Doug -Original Message- From: Sterling K. Webb <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Cc: meteorite-list@meteoritecentral.com; [EMAIL PROTECTED] Sent: Sat, 5 Apr 2008 1:23 am Subject: Re: [meteorite-list] New, long, Carancas article II Hi, In this context "contained" means contained by the back pressure envelope of the shock wave. The meteoric material would be far enough away from the shock not be heated very much. The shock wave at the sides is the hot stuff from the front and it's cooling down rapidly. Even in the entry of a spherical object the back side is not ablated. The melted rock on the back is running fluid from the front, not backside material that melted. And there's many a fine crusty meteorite whose back side is hardly touched by melt even though it's only a few inches away from the fire of re-entry. The shock wave is the boundary between material moving faster than sound (traveling with the meteoroid) and material not moving faster than sound (the surrounding atmosphere). Check the Wikipedia entry (very good discussion): http://en.wikipedia.org/wiki/Shock_wave "Shock waves are characterized by an abrupt, nearly discontinuous change in the characteristics of the medium. Across a shock there is always an extremely rapid rise in pressure, temperature and density of the flow." In other words, just a little too close and you're dead meat! Just an inch away, you're OK. The faster an object goes, the more sharply bent back the shock wave is; as it slows, the shock wave stands out further away, until at the speed of sound it's at right angles to the direction of flight. As long as the sides of object are on the "right" side of the fiery shock wave, it's safe from being melted at least. It's like being the heat shadow. Both Schultz and I calculate that the object was still supersonic when it hit, still enclosed in a "detached" shock wave, so the sides never ablated at any point. Sterling K. Webb --- - Original Message - From: <[EMAIL PROTECTED]> To: "Sterling K. Webb" <[EMAIL PROTECTED]> Cc: ; <[EMAIL PROTECTED]> Sent: Saturday, April 05, 2008 12:44 AM Subject: Re: [meteorite-list] New, long, Carancas article II It would seem to me that if the stone fragmented in flight and was contained by the shock wave it would still be heated by the plasma and all the fragments would develop crusts. There appear to be some pieces with crust, but enought to match Schultz's theory? "Sterling K. Webb" <[EMAIL PROTECTED]> wrote: Schultz and I both agree that a greater aerodynamic efficiency will get a chondrite to the ground faster with less loss of material, making an impact like Carancas possible. What Schultz proposes is that the fragile material of Carancas fragmented early on but did not "pancake" out and cause an airburst, but was wrapped by the shock wave around the hypersonic meteoroid into a "bullet" shape that stayed together and kept its high speed to the ground. What I proposed was that the Carancas impactor was an elongated fragment to begin with. That is, it was a "sliver" of asteroid that was 4 or 5 times longer than its width when it entered the Earth's atmosphere.
Re: [meteorite-list] Atmospheric ablation marks on Tektites?
Michael, Yep - it's amazing that something so simple as a piece of glass has caused so much churning for over 100 years. The vast majority agrees they are of cosmic origin, most believe that they are from impacts on earth, but there are still those that believe the moon is directly involved. I've also read some other bizarre ideas - the coolest of them (to me) was the idea that the reason tektites are not always formed is that maybe they come from the impact of a huge ball of silica glass that slams into earth - A big meteorite just made of glass... how cool would that be. So far, everything I read simply states that tektites come from multiple sources. And don't worry about the "noob" stuff - I've only been diving into this for a few months, so I'll still say something way off base (as Doug points out with my "still a lot of debate" comment.) It's almost always wrong to make any general statement about tektites as a whole... the LDG debate is still ongoing as to how it was formed, but most people tie it to an impact event, and as an impactite. I've seen pictures (and have a few pieces) of LDG that show some of the splash-form types of characteristics of tektites, but nothing with a "crust" or a true regmaglypts. - Tektite and impactite - different animals. - LDG and Darwin glass - Terrestrial - it really helps that there are inclusions that are of the local material stuck in them. They also have a slightly higher concentration of water (in ppm) that make them different than a true tektite. The shaping that is seen in those glasses is not as nearly as convincing as the Australasian glasses. -Ventifacts is the more correct answer. But considering the company that tektites keeps with our other cosmic collectibles, I'm gonna stick with pseudo-regmaglypts until someone beats me up. - Yes - there are a lot of good documentation that spells out the composition of tektites. (Get Povenmire's book and McCall's book). The chemical composition of the tektites is the thing that really drives a lot of the controversy. The glass, in many cases, is very pure and free of water - it's hard to say how it was made since it breaks a few of the glass making rules and regulations :) They have found tektite like material on the moon (if it was found here on earth no one would have argued that it was not a tektite), but they are very small. It was thought that the first trips to the moon would have seen and brought back big, standard lots of tektites if that is where the originated - but they did not. many people changed their minds on the lunar origin after the moon landings. When they found microtektites on the moon, they ascribed them to impacts on the moon... after all, it is generally accepted that the moon and the earth are made from each other, so there will always be similarities. Another fun origin note: John O'Keefe was another of the proponents of the lunar origin of tektites. He died in 2000, and on his funeral program he had wanted the following phrase added: "Tektitae De Luna Sunt!" - "tektites are from the moon!" That's conviction. Sean. - Original Message - From: "Michael Gilmer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: Sent: Saturday, April 05, 2008 11:07 AM Subject: Re: [meteorite-list] Atmospheric ablation marks on Tektites? Hi! Ok, now I figuring out this tektite issue. I want to thank everyone for their kind informative responses. First, I had no idea that tektites were so controversial! Well, I did have *some* idea, but I thought it was generally accepted by the meteorite community that tektites of all types were impact artifacts and were not the product of atmospheric-entry or extra-terrestrial processes. I knew that there were alternate theories for the origins of tektites, but I thought these theories were mostly fringe in nature and not commonly accepted by the Met community at large. It appears I have a lot more reading to do on tektites. "Ventifact" does indeed seem to be the best term available to describe regmaglypt-like features on LDG and other similar glasses. Features that suggest orientation or flow-lines are also wind-driven ventifacts I assume. As others said though, this does not reasonably explain the appearance of "button" tektites of the Australite variety. Although I must admit, the first time I saw a button-type tektite, my first thought was not atmospheric-ablation or sculpting. My first thought was a splatter-type impact artifact. If you have ever taken a spoonfull of viscous batter and dropped it on the floor, the outer edges of the mass will spread outward while the central area is uplifted somewhat. I had erringly assumed that similar physics were at work with the button-types. Perhaps a massive detonation on impact liquified a combination of meteorite and earthly-minerals which were blasted upwards and then fell back to earth - forming into a button when the material hit the ground
[meteorite-list] Mount Tazerait, Is it obtainable?
Hi List, I recently imaged a thin section of Mount Tazerait L5. I found it fell Aug 21 1991 in Niger but I haven't seen any for sale (since I started looking which was just recently). Is this a hard one to find? In the thin section was a large inclusion. I have many cool micrographs of it on the March Meteorite Times issue (Open the magazine and click on Micro Visions). http://www.meteorite-times.com/meteorite_frame.htm This inclusion was different from what I am used to seeing and reminded me of some Earth like volcanic structures. I won't start tossing descriptive names around because I might be way off. Any of you with the time and inclination, please share your thoughts of what this stuff reminds you of. And if any one knows of Mount T for sale, please let me know. Thanks, Tom Phillips **Planning your summer road trip? Check out AOL Travel Guides. (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Atmospheric ablation marks on Tektites?
Hi Norm, Running a little slow in my emails, thanks for the (much earlier) reply and nice to see you're still in touch... Best wishes, Doug -Original Message- From: Norm Lehrman <[EMAIL PROTECTED]> To: Michael Gilmer <[EMAIL PROTECTED]>; meteorite-list@meteoritecentral.com Sent: Fri, 4 Apr 2008 9:16 pm Subject: Re: [meteorite-list] Atmospheric ablation marks on Tektites? Mike, I'm not aware of any LDG that retains preserved external primary skin, so we don't even know what morphology or skin LDG may have once had. What you see now is mostly the result of desert sand-blasting by saltating sand grains. It can look "oriented", and indeed it is, but with respect to prevailing surface winds, not atmospheric re-entry. Many pieces of LDG can properly be termed "ventifacts". The australasians, and in particular, the australites certainly do have all sorts of thermal ablasian features, and when it comes to orientation, flanged buttons exceed the perfection of any meteorite. This is "orientation" exactly as we intend the word in meteoritics. With tektite discussions, one answer rarely fits all--- Cheers, Norm (of http://tektitesource.com , temporarily on hold while we are stationed in Tanzania for a few years). --- Michael Gilmer <[EMAIL PROTECTED]> wrote: Hi Group! While reading through another Meteorite-related message board on the WWW, I ran across a statement by an IMCA member that puzzles me somewhat. A discussion about Libyan Desert Glass was ongoing, and we were sharing photos of our LDG specimens. (and I showed off my new 9+ gram piece of dark-veined glass from Michael Farmer - thanks Mike!) So the guy says : "This is one of my favorites and is fully oriented with regmaglypts (yes, tektite impactites can have atmospheric ablation patterns too)." Ok, here is my confusion - I was under the impression that tektites were formed on impact - on Earth. So, doesn't this mean they cannot have atmospheric ablation patterns? Assuming the tektite never passed through the atmosphere, I don't see how this is possible. I have seen tektites with features that resemble regmaglypts and orientation, but this is just chance occurence, right? Or do I need to be schooled here? Thanks in advance! MikeG _ ___ You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Atmospheric ablation marks on Tektites?
On "regmaglypts" in LDG... Sean M. wrote: "I called them "Pseudo" in the description, because, well, there is still a lot of debate about them being formed from traveling through the atmosphere" Hello, "Still a lot of debate"? Could you kindly elaborate where atmospheric aerodynamic shaping for LDG ever was (maybe) or stilli is (huh??) being seriously debated by anyone who can tell the difference between a tektite and a chard of a beer bottle? ==>With so many tons and never an inkling of any fusion crust or other surface shaping? ==>With a water content indicating the glass was not formed in space like other tektites. In answer to the prior question, regmaglypts are usually formed dues to differences in material as the theory goes (edges of sharp breaks get rounded, but those shapes aren't regmaglypts - and variation of true regmaglypting rates during its removal during ablation. Meanwhile, tektites, and for that matter LDG is essentially uniform so the mechanism to form regmaglypts would have to be by thinking a bit more out of the box... Best wishes, Doug -Original Message- From: Sean T. Murray <[EMAIL PROTECTED]> To: meteorite-list@meteoritecentral.com Sent: Fri, 4 Apr 2008 9:13 pm Subject: Re: [meteorite-list] Atmospheric ablation marks on Tektites? Ok folks - I want plenty of comments on this mess :) One of my favorite topics... Let's see if I can ramble through this... Most tektites, by definition, have passed through the atmosphere at least once. Some material (depending on the theory you believe in) just is spit out in the form of blobs of glass, but others take the long trip through the atmosphere to gain their unique shapes. There are still people on both sides of the fence as to the origin of tektites. The majority of the folks think they happen on impact here on earth and that the material is thrown out of the atmosphere and then re-enters to create many of the aerodynamic shapes we see in typical tektites. The other theory is that tektites were formed from lunar events (such as volcanic eruptions) and enter the atmosphere on earth and gain much of their shapes on the trip through. There is a lot of reading material out there that talk about both theories. The main flaw in the impact theory has to do with Stokes Law (for creating glass) and the lack of a discovered crater for the Australasian event (the crater should be massive considering tektites from that event covered about 20% of the planet). The lunar theory has it's share of problems as well. You should read Hal Povenmire's book. It's got a lot of interesting information on tektites. I also love this website: http://www.tektites.co.uk/index.html - there is a good set of pages that describe the formation of the shapes and features on tektites (http://www.tektites.co.uk/22.html). However, in the case of LDG, a point to make is that I've seen multiple people argue that they are not actually tektites, but are instead impact glass. Most impact glass definitions that I have seen don't require that the material has been in and out of the atmosphere at least once. However, it is hard to argue with the features on the LDGs. I have a piece that has "regmaglypts" that rival any Sikote you can find (thanks to Mike as well! http://www.rocksfromspace.org/March_23_2008.html). I called them "Pseudo" in the description, because, well, there is still a lot of debate about them being formed from traveling through the atmosphere, or just weathering out due to natural weaknesses imposed by the cooling, impact, and subsequent chemical etching (fresh water mainly) and/or sandblasting over the years. I'd love to hear some other opinions. There is another source that I have not started reading yet - Joe McCall's book on tektites. He does have a chapter that singles out Darwin glass and LDG. Sean. - Original Message - From: "Michael Gilmer" <[EMAIL PROTECTED]> To: Sent: Friday, April 04, 2008 10:36 PM Subject: [meteorite-list] Atmospheric ablation marks on Tektites? Hi Group! While reading through another Meteorite-related message board on the WWW, I ran across a statement by an IMCA member that puzzles me somewhat. A discussion about Libyan Desert Glass was ongoing, and we were sharing photos of our LDG specimens. (and I showed off my new 9+ gram piece of dark-veined glass from Michael Farmer - thanks Mike!) So the guy says : "This is one of my favorites and is fully oriented with regmaglypts (yes, tektite impactites can have atmospheric ablation patterns too)." Ok, here is my confusion - I was under the impression that tektites were formed on impact - on Earth. So, doesn't this mean they cannot have atmospheric ablation patterns? Assuming the tektite never passed through the atmosphere, I don't see how this is possible. I have seen tektites with features that resemble regmaglypts and orientation, but this is just cha
Re: [meteorite-list] Meteorite-list Digest, Vol 54, Issue 13
OMG! That can't be safe! Are these people in the video still alive? MikeG -- I am not sure if this was posted before, if not it is great fun. http://etching-meteorite-seymchan.blogspot.com/ Laurence You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Atmospheric ablation marks on Tektites?
Hi! Ok, now I figuring out this tektite issue. I want to thank everyone for their kind informative responses. First, I had no idea that tektites were so controversial! Well, I did have *some* idea, but I thought it was generally accepted by the meteorite community that tektites of all types were impact artifacts and were not the product of atmospheric-entry or extra-terrestrial processes. I knew that there were alternate theories for the origins of tektites, but I thought these theories were mostly fringe in nature and not commonly accepted by the Met community at large. It appears I have a lot more reading to do on tektites. "Ventifact" does indeed seem to be the best term available to describe regmaglypt-like features on LDG and other similar glasses. Features that suggest orientation or flow-lines are also wind-driven ventifacts I assume. As others said though, this does not reasonably explain the appearance of "button" tektites of the Australite variety. Although I must admit, the first time I saw a button-type tektite, my first thought was not atmospheric-ablation or sculpting. My first thought was a splatter-type impact artifact. If you have ever taken a spoonfull of viscous batter and dropped it on the floor, the outer edges of the mass will spread outward while the central area is uplifted somewhat. I had erringly assumed that similar physics were at work with the button-types. Perhaps a massive detonation on impact liquified a combination of meteorite and earthly-minerals which were blasted upwards and then fell back to earth - forming into a button when the material hit the ground again. Again, I expose my ignorance here. And I am glad I came to the list with this question. :) So while we are on the subject and educating a newbie here, let me ask a couple of tektite-related questions for the record, so to speak. 1) tektite and impactite - interchangeable terms or different animals? 2) desert glass, darwin glass - terrestrial or not? 3) When describing aesthetic features present on a tektite/impactite that resemble atmospheric effects, should one use the term "pseudo-regmaglypts" or "ventifacts"? Or should one go ahead and use the same terminology used to describe these features in meteorites? (orientation, flowlines, etc) 4) have impactites/tektites ever been studied in-depth in the lab to determine their exact source? It seems to me a minor mystery to solve. We can compare chemistries of specimens to determine a lunar or martian origin, but we lack the science to determine where a tektite formed? I'm surprised this is still a "controversial" issue - modern science has peeled back the layers of confusion on deeper mysteries than this. Thanks in advance for putting up with this newbies inquiries! MikeG --- [EMAIL PROTECTED] wrote: > Hello Mike and List, > > There is some confusion here. > Libyan Desert Glass is an impact glass, not a > tektite. > It is 20-30 millions years old, has gone thru many > changes in climate and > conditions in their corner of the Sahara. But in the > last few thousands of > years, it has mostly been shaped/ablated/sculpted by > zillions of sand storms. > More like Ventrifacts really > Does that help? > > Anne M. Black > www.IMPACTIKA.com > [EMAIL PROTECTED] > Vice-President of IMCA > www.IMCA.cc > > > In a message dated 4/4/2008 8:37:13 PM Mountain > Daylight Time, > [EMAIL PROTECTED] writes: > Hi Group! > > While reading through another Meteorite-related > message board on the WWW, I ran across a statement > by > an IMCA member that puzzles me somewhat. A > discussion > about Libyan Desert Glass was ongoing, and we were > sharing photos of our LDG specimens. (and I showed > off my new 9+ gram piece of dark-veined glass from > Michael Farmer - thanks Mike!) > > So the guy says : > > "This is one of my favorites and is fully oriented > with regmaglypts (yes, tektite impactites can have > atmospheric ablation patterns too)." > > Ok, here is my confusion - I was under the > impression > that tektites were formed on impact - on Earth. > So, > doesn't this mean they cannot have atmospheric > ablation patterns? Assuming the tektite never > passed > through the atmosphere, I don't see how this is > possible. > > I have seen tektites with features that resemble > regmaglypts and orientation, but this is just > chance > occurence, right? > > Or do I need to be schooled here? > > Thanks in advance! > > MikeG > > > > > **Planning your summer road trip? Check > out AOL Travel Guides. > > (http://travel.aol.com/travel-guide/united-states?ncid=aoltrv000316) > You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com
Re: [meteorite-list] fun meteorite video
Great Video! I wonder how many they are able to etch before their skin falls off or their lungs are seared - no gloves, no mask. Where does the spent Nitol go?? Still a great video. Dave --- Laurence Garvie <[EMAIL PROTECTED]> wrote: > I am not sure if this was posted before, if not it > is great fun. > > http://etching-meteorite-seymchan.blogspot.com/ > > Laurence > > __ > http://www.meteoritecentral.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. http://tc.deals.yahoo.com/tc/blockbuster/text5.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article
At least 5 to 6 kilos was dust, I know of about 4 kilos of fragments. Mike --- Jeff Kuyken <[EMAIL PROTECTED]> wrote: > Hey Mike & all. Is there any idea how much of that > ~10kgs was in the dust > form? I heard that there was more dust than decent > fragments but don't know > if that's true. > > Cheers, > > Jeff > > > - Original Message - > From: "Michael Farmer" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; > > Cc: <[EMAIL PROTECTED]> > Sent: Saturday, April 05, 2008 2:46 AM > Subject: Re: [meteorite-list] New, long, Carancas > article > > > > Yeah, like most reporters, they always mess things > up. > > I told them that a total of ~10 kilos was > recovered. > > mike > > > > > > --- Darren Garrison <[EMAIL PROTECTED]> wrote: > > > >> Hey, Mike, did you know that you and your team of > >> poachers recovered 10 kilos of > >> Carancas? > >> > >> > > > http://media.www.browndailyherald.com/media/storage/paper472/news/2008/04/04/Features/Professor.Solves.A.Meteor.Mystery-3304236.shtml > >> > >> Professor solves a meteor mystery > >> By: Chaz Firestone > >> Posted: 4/4/08 > >> Last September, something strange landed near the > >> rural Peruvian village of > >> Carancas. Two months later, so did Peter Schultz. > >> > >> One was an extraterrestrial fireball that struck > the > >> Earth at 10,000 miles per > >> hour, formed a bubbling crater nearly 50 feet > wide > >> and afflicted local villagers > >> and livestock with a mysterious illness. The > other > >> is the Brown geologist who > >> may have figured out why. > >> > >> The fiery mass shot across the morning sky > bursting > >> and crackling like > >> fireworks, villagers said after the Sept. 15 > impact. > >> An explosive crash tossed > >> nearby locals to the ground, shattered windows > one > >> kilometer away and kicked up > >> a massive dust cloud, covering one man from head > to > >> toe in a fine white powder. > >> Many thought the streaking fireball - brighter > than > >> the sun, by some accounts - > >> was an aerial attack from neighboring Chile. > >> > >> Curious shepherds and farmers approached the > crash > >> site to find a smoking crater > >> reminiscent of a Hollywood film, laden with rocks > >> and stirring with bubbling > >> water that emitted a foul vapor. But curiosity > >> turned to fear when unexplained > >> symptoms began to crop up in Carancas: headaches, > >> vomiting and skin lesions > >> struck more than 150 villagers, Peru's Ministry > of > >> Health stated days later. > >> Locals reported that their animals lost their > >> appetites and bled from their > >> noses. Children were restless and cried through > the > >> night. > >> > >> But according to Schultz, the professor of > >> geological sciences who visited the > >> site last December, the true mystery in Carancas > is > >> how any of this happened in > >> the first place. > >> > >> Sophisticated theory and conventional wisdom have > >> long agreed that most meteors > >> break into fragments and fizzle out before they > can > >> reach the Earth's surface. > >> Even those large and durable enough to make it > >> through the atmosphere hit the > >> ground as ghosts of their former selves, > "plopping > >> out of the sky and forming a > >> bullet hole in the Earth," Schultz said. "This > >> meteor crashed into the Earth at > >> three kilometers per second, exploded and buried > >> itself into the ground." > >> > >> Last month, Schultz delivered a highly > anticipated > >> lecture at the 39th Lunar and > >> Planetary Science Conference in League City, > Texas. > >> And if he's right, the bold > >> theory he proposed there may shake loose a "gut > >> response" entrenched within the > >> geological, physical and astronomical sciences: > >> "Carancas simply should not have > >> happened." > >> > >> > >> > >> A Web of speculation > >> > >> The handful of shepherds who happened to lead > their > >> Alpaca herds near the arroyo > >> that day may have been the first humans ever to > >> witness an explosive meteor > >> impact. But the rest of the world quickly got its > >> chance, if vicariously, > >> through a flurry of activity in the blogosphere. > >> > >> Hundreds of scientists, journalists and > captivated > >> amateurs weighed in on the > >> bizarre events as they unfolded, offering scores > of > >> pet theories and radically > >> revising them as more information streamed in > from > >> Peru. > >> > >> Pravda, a Russian online newspaper born out of a > >> print version run by the > >> country's former Communist Party, ran the > headline > >> "American spy satellite > >> downed in Peru as U.S. nuclear attack on Iran > >> thwarted" five days after the > >> impact. The story attributes the villagers' > illness > >> to radiation poisoning from > >> the satellite's plutonium power generator. > >> > >> Other proposed explanations were less > sensational. > >> Nevadan wildlife biologist > >> and amateur geologist David Syzdek wrote a Sept. > 18 > >> blog post titled "M
Re: [meteorite-list] Monthly Favourite
Wow! Any for sale??? If yes, please reply OFF list. ;>) Cheers, Mike Tettenborn - Original Message - From: "Jeff Kuyken" <[EMAIL PROTECTED]> To: "Meteorite List" Sent: Saturday, April 05, 2008 2:43 AM Subject: [meteorite-list] Monthly Favourite Hi all, I'm playing catch-up so here is February 2008. ;-) http://www.meteorites.com.au/favourite.html Cheers, Jeff __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Rocks from Space Picture of the Day - April 5, 2008
http://www.rocksfromspace.org/April_5_2008.html __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] New, long, Carancas article II
Hi, In this context "contained" means contained by the back pressure envelope of the shock wave. The meteoric material would be far enough away from the shock not be heated very much. The shock wave at the sides is the hot stuff from the front and it's cooling down rapidly. Even in the entry of a spherical object the back side is not ablated. The melted rock on the back is running fluid from the front, not backside material that melted. And there's many a fine crusty meteorite whose back side is hardly touched by melt even though it's only a few inches away from the fire of re-entry. The shock wave is the boundary between material moving faster than sound (traveling with the meteoroid) and material not moving faster than sound (the surrounding atmosphere). Check the Wikipedia entry (very good discussion): http://en.wikipedia.org/wiki/Shock_wave "Shock waves are characterized by an abrupt, nearly discontinuous change in the characteristics of the medium. Across a shock there is always an extremely rapid rise in pressure, temperature and density of the flow." In other words, just a little too close and you're dead meat! Just an inch away, you're OK. The faster an object goes, the more sharply bent back the shock wave is; as it slows, the shock wave stands out further away, until at the speed of sound it's at right angles to the direction of flight. As long as the sides of object are on the "right" side of the fiery shock wave, it's safe from being melted at least. It's like being the heat shadow. Both Schultz and I calculate that the object was still supersonic when it hit, still enclosed in a "detached" shock wave, so the sides never ablated at any point. Sterling K. Webb --- - Original Message - From: <[EMAIL PROTECTED]> To: "Sterling K. Webb" <[EMAIL PROTECTED]> Cc: ; <[EMAIL PROTECTED]> Sent: Saturday, April 05, 2008 12:44 AM Subject: Re: [meteorite-list] New, long, Carancas article II It would seem to me that if the stone fragmented in flight and was contained by the shock wave it would still be heated by the plasma and all the fragments would develop crusts. There appear to be some pieces with crust, but enought to match Schultz's theory? "Sterling K. Webb" <[EMAIL PROTECTED]> wrote: Schultz and I both agree that a greater aerodynamic efficiency will get a chondrite to the ground faster with less loss of material, making an impact like Carancas possible. What Schultz proposes is that the fragile material of Carancas fragmented early on but did not "pancake" out and cause an airburst, but was wrapped by the shock wave around the hypersonic meteoroid into a "bullet" shape that stayed together and kept its high speed to the ground. What I proposed was that the Carancas impactor was an elongated fragment to begin with. That is, it was a "sliver" of asteroid that was 4 or 5 times longer than its width when it entered the Earth's atmosphere. The results would be the same: a faster trip to the ground in (mostly) one piece. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Ad - Meteorites for sale
Hello fellow listees, I am putting 7 of my meteorites up for sale. I am a motivated seller so just make me an offer and you might be surprised at what I will accept. 18.7 gram fragment of Beaver Creek (H5) - hard to find Canadian meteorite 33.5 full slice of NWA 1929 (Howardite) 5.4 gram part slice of Abee (EH4) 95 gram part slice of Chinga (Ataxite) 87.7 gram part slice of NWA 2224 (CV3) 5.27 gram part slice of Kapeota (Howardite) 20.7 gram full slice of unclassified Eucrite or Howardite Please email me for photos and for any additional information. Thank you, Jake Pelletier IMCA # 6168 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
