[meteorite-list] /Sale/ Glorieta Pallasite end cut /AD/
Hi everyone I have a 299 gram pallasite end cut for sale @ $3500. The shape is even better than it looks on camera at $3500 it is under $12 per gram. First one to email with the $3500 takes it. Thanks Here is a link http://s146.photobucket.com/albums/r249/meteoritefinder/ Mike Miller Po Box 314 Gerber Ca 96035 www.meteoritefinder.com 530-384-1598 __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Exploration Rover Update - April 17, 2007
http://marsrovers.jpl.nasa.gov/mission/status.html#opportunity OPPORTUNITY UPDATE: Investigating a Dark Streak - sol 1139-1144, April 17, 2007: Opportunity is healthy and spent the last week investigating the dark material trailing north from Victoria Crater. The plan this week included two brief robotic arm campaigns at different areas roughly 33 meters (108 feet) apart. Opportunity will collect a series of microscopic images and alpha particle X-ray spectrometer integrations on the soil along with other remote science observations. Sol-by-sol summary: Each sol starts with a panoramic camera tau and miniature thermal emission spectrometer mini sky and ground stare right after handing over from the previous sol's master sequence. At the end of each sol's plan, right before transitioning to the following sol, there is a navigation camera bitty cloud observation and a miniature thermal emission spectrometer mini sky and ground stare. Sol 1139 (April 8, 2007): Opportunity conducted remote sensing on the dark streak. The rover then took stereo microscopic images of Palencia and Pontevedra. Opportunity then moved its robotic arm out of the way to prepare for argon integration position. The panoramic camera was then used to image the rover tracks. The rover began alpha particle X-ray spectromter argon integration. Opportunity then had a mini deep sleep. After waking, the rover looked for clouds with its navigation camera. The panoramic camera was used to image the sky. Sol 1140: On this sol, Opportunity continued to conduct remote sensing on the dark streak. The rover then placed the alpha particle X-ray spectrometer on the soil. The panoramic camera conducted some photometry, then took a 13-filter image of track target Zamora. The miniature thermal emission spectrometer examined Zamora and then the undisturbed soil behind it. The alpha particle X-ray spectrometer was then placed on the soil. The rover then went into deep sleep. Sol 1141: Opportunity continued remote sensing on the dark streak. The panoramic camera took a panoramic image to test for albedo (light reflectivity). The miniature thermal emission spectrometer did a 7-point sky ground stare. Before the Mars Odyssey pass, the panoramic camera was used for photometry experiments. The miniature thermal emission spectrometer conducted an elevation sky ground stare and then it stared at the calibration target. After a deep sleep, the navigation camera looked for clouds in the sky. Sol 1142: On the morning of this sol, the miniature thermal emission spectrometer conducted a mini sky ground stare. The rover then drove 31.23 meters (102.5 feet) to a second location in the dark streak. The navigation camera imaged a future robotic arm target and the panoramic camera imaged a future drive direction and then took a tau measurement. Sol 1143: Opportunity bumped 2.21 meters (7.3 feet). The panoramic camera took a tau measurement and the miniature thermal emission spectrometer did a sky and ground stare. Before it moved again, Opportunity took a 13-filter panoramic camera image of target Alicante. The rover then stowed its arm and drove about 3 meters (9.8 feet) to Alicante. Opportunity then unstowed its arm and autoplace software put it on Alicante. A microscopic image mosaic of Alicante was taken. The Moessbauer spectrometer did a quick touch of Alicante before the alpha particle X-ray spectrometer was placed on the target. Before the Odyssey pass, the panoramic camera took a tau measurement. During the orbiter's pass, Opportunity's miniature thermal emission spectrometer did a sky and ground stare. After the Odyssey pass, the alpha particle X-ray spectrometer was integrated on target Alicante. Sol 1144: This sol saw more remote sensing on the dark streak. The panoramic camera took a tau measurement, the miniature thermal emission spectrometer did a sky and ground stare. The panoramic camera took a 13-filter image of Avila, and then the miniature thermal emission spectrometer stared at the same target. Before the Odyssey pass, the panoramic camera took another tau measurement. During the pass, the miniature thermal emission spectrometer conducted an elevation sky and ground stare. The rover then went into deep sleep. Current Odometry: As of sol 1143, Opportunity's total odometry is 10,443.41 meters (6.5 miles). __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - April 15, 2007
http://dawn.jpl.nasa.gov/mission/journal_4_07.asp Dawn Journal Dr. Marc D. Rayman April 15, 2007 Dear Dawnthecoasts, The Dawn spacecraft has completed its longest terrestrial journey on its path to asteroid Vesta and dwarf planet Ceres. While it will be propelled by exotic ion propulsion during most of its mission, this segment of its travels was accomplished using decidedly more conventional chemical propulsion. After being packed with great care at the Naval Research Laboratory (NRL) in Washington, DC, the spacecraft and a great deal of additional equipment left on a truck a few hours before dusk on April 9. Less than 18 hours later, a few hours after dawn, it arrived at its home for the next two months, Astrotech Space Operations in Titusville, Florida, near Cape Canaveral. When last we checked in with the spacecraft, it had completed an extensive series of tests in a thermal vacuum chamber at NRL. The pace of activities has not let up since then, with engineers and technicians rarely letting the spacecraft have a rest. Myriad tasks are being completed and checked off the long and carefully planned list of steps necessary before the probe may begin its ambitious mission in harsh and remote parts of the solar system. For example, thorough checks for any possible leaks in the ion propulsion system and the reaction control system (the system that uses small conventional thrusters to aid in orienting the spacecraft in the zero-gravity of spaceflight) verified their integrity, certifying them for many years of operation in space. More tests have been conducted to confirm the flow of information between the many elements of the mission control systems and all of the computers onboard the spacecraft. As expected, some of the thermal vacuum tests had revealed the need to make some minor changes in a few of the 9000 wires connecting different elements of the spacecraft. As these updates were in progress, the device that controls the high voltage, high power electricity from Dawn's large solar arrays was removed from the spacecraft and shipped to JPL. There is always a risk of accidentally damaging hardware or introducing an error, even in ways that may not be noticed immediately. Therefore, after this unit was modified, it was subjected to additional vibration testing as well as operation in a thermal vacuum chamber. These tests showed the complex assembly to be in fine health and ready for flight, and it was returned to the spacecraft in March. In the same vein, to ensure that no subtle problems crept in as a consequence of the work to remove or reinstall this device, the spacecraft underwent another acoustic test at NRL similar to one it experienced in November 2006. The spacecraft will be subjected to deafening sound waves during its climb to space. At the beginning of this month, Dawn had another preview of this reverberant environment in a test that demonstrated the entire system was intact and ready for a rocket trip to space (or an evening in a mosh pit). Following its outstanding performance, the spacecraft was rewarded, as had been promised nearly a year ago, with an all-expense-paid spring vacation in Florida. Dawn is now in the perfect location, near sandy beaches, warm ocean waters, facilities for loading hazardous fuels, and other attractions. Just as the spacecraft has been following a rigorous schedule of building, testing, checking, and rechecking, the many elements of its Delta II 7925H-9.5 rocket have been undergoing similarly demanding procedures. This version of the venerable Delta series of rockets has not been launched since 2004, but now it is nearly ready again to make the brief but arduous flight from Cape Canaveral to outer space. To accommodate a change in the schedule for readying Dawn's rocket, the planned launch date has been shifted from June 20 to June 30. This change will have no significant effect on the plans for the mission, including when the spacecraft will arrive at its celestial targets. The timetable at Space Launch Complex 17 allows Dawn to launch as late as July 19, with the exact date of liftoff depending on the weather as well as the cooperation of millions of components of hardware and software on the rocket, the spacecraft, mission control, range safety, communications systems around the world, and more. Dawn's launch will occur around 5:00 pm EDT, but the precise times that are possible will not be determined until early June. Readers may find launch times down to the second in print, on the web, or, to our embarrassment, on graffiti in the asteroid belt, but those times were based on preliminary estimates and will change. Engineers now are working through the complex analyses necessary to establish the exact times the launch window will open and close on each day of Dawn's 20-day launch period. These analyses incorporate refinements and updates such as the spacecraft's mass at launch, the thrust and efficiency of the ion propulsion
Re: [meteorite-list] /Sale/ Glorieta Pallasite end cut /AD/
Mike, that really helps me sell Glorietta from you guys, selling it publicly for less than it was offered to me! I don't appreciate the fact that now the public price for glorietta is $11.70 gram. Mike --- Mike Miller [EMAIL PROTECTED] wrote: Hi everyone I have a 299 gram pallasite end cut for sale @ $3500. The shape is even better than it looks on camera at $3500 it is under $12 per gram. First one to email with the $3500 takes it. Thanks Here is a link http://s146.photobucket.com/albums/r249/meteoritefinder/ Mike Miller Po Box 314 Gerber Ca 96035 www.meteoritefinder.com 530-384-1598 __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Angrite Impact - NWA 4590 Tamassint
Dear Angrite Lovers, Count down is at 1hr 50min. until the new angrite, NWA 4590, start to end. It will be fun to see what kind of last minute action this one gets. The 66g main mass currently has 345 unique views! Good Luck to the bidders, snipers and those who are just watching! Best regards, Greg Greg Hupe The Hupe Collection NaturesVault (eBay) [EMAIL PROTECTED] www.LunarRock.com IMCA 3163 __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Angrite NWA 4590 auctions have ended now, ...
.. and I am glad I did not jump on the lower opening price so that the piece that was my perfect size has not been lost to another bidder! I received mine (1.024 grams) today. It sports patches of shiny, glossy fusion crust today and it is a pleasure to hold and a feast for the eyes to behold! Will have to wait for the weekend before I find some time to read the Lunar and Planetary abstract on NWA 4590 and look at this little gem under my stereo microscope. Wish I had a thin section of this gorgeous plutonic angrite. The mottled appearance of the NWA 4590 crystals in cross-polarized light resembles that of the NWA 3151 brachinite but the crystals are substantially larger in this *plutonic* angrite and there is much more plagioclase (almost pure anorthite): http://www.lunarrock.com/nwa4590/nwa4590xpl.jpg Best wishes, Angritically, Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Kalahari 009 (lunar) photo
Here's a photo of the whole Kalahari 008 stone: http://meteorites.wustl.edu/lunar/stones/kalahari008.htm I don't think I would have picked it up, and I sure wouldn't have even considered that it might be a lunar meteorite. Randy Korotev At 03:40 11-04-07 Wednesday, you wrote: Hi, This has all probably been on the list before...but I was not following it at the time...so have these lunar meteorites just disappeared without trace? Has anyone ever seen photographs of the main masses and where are they now.? Have any pieces come on to the market ever? Graham Ensor, nr Barwell UK __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Kalahari 009 (lunar) photo
Mah. MC - Original Message - Da : Randy Korotev [EMAIL PROTECTED] A : meteorite-list@meteoritecentral.com Oggetto : [meteorite-list] Kalahari 009 (lunar) photo Data : Wed, 18 Apr 2007 15:24:30 -0500 Here's a photo of the whole Kalahari 008 stone: http://meteorites.wustl.edu/lunar/stones/kalahari008.htm I don't think I would have picked it up, and I sure wouldn't have even considered that it might be a lunar meteorite. Randy Korotev At 03:40 11-04-07 Wednesday, you wrote: Hi, This has all probably been on the list before...but I was not following it at the time...so have these lunar meteorites just disappeared without trace? Has anyone ever seen photographs of the main masses and where are they now.? Have any pieces come on to the market ever? Graham Ensor, nr Barwell UK __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] /Sale/ Glorieta Pallasite end cut /AD/
I have a question and I'm not trying to stir up any kind of trouble. Does the presence of a few olivine crystals make this specimen a pallasite? Or is that why you are offering it for just a little more then your siderite samples? __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Kalahari 009 (lunar) photo
--- M come Meteorite Meteorites [EMAIL PROTECTED] wrote: Mah. MC Mah? Persian god of the moon and queen of the night __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Kalahari 009 (lunar) photo
Classification and mineralogy (...): olivine, Fa63±18; pyroxene Fs42±10; plagioclase An85-98. The shock stage of the rock is S4, the weathering grade is W1. wt.%: Al: 14.68; Si: 20.73; Mg: 2.68; Fe: 3.5; Ca: 11.1. Thanks for posting the photo and the nice web page Randy. Would you know how a weathering grade was assigned (probably there is more to this seeing it was classified at Wlotzka's Max Planck) , I wonder how much iron and FeS of the 3.5% Fe was actually available/useful to this end? W1 is statistically quite a nice rating to fall off the turnip truck, wouldn't a simple Antarctic A be more appropriate? Best Wishes and Good Health, Doug - Original Message - From: Randy Korotev [EMAIL PROTECTED] To: meteorite-list@meteoritecentral.com Sent: Wednesday, April 18, 2007 3:24 PM Subject: [meteorite-list] Kalahari 009 (lunar) photo Here's a photo of the whole Kalahari 008 stone: http://meteorites.wustl.edu/lunar/stones/kalahari008.htm I don't think I would have picked it up, and I sure wouldn't have even considered that it might be a lunar meteorite. Randy Korotev At 03:40 11-04-07 Wednesday, you wrote: Hi, This has all probably been on the list before...but I was not following it at the time...so have these lunar meteorites just disappeared without trace? Has anyone ever seen photographs of the main masses and where are they now.? Have any pieces come on to the market ever? Graham Ensor, nr Barwell UK __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD - eBay - not Zagora(!), similar to NWA 2680(?) or a new iron...
http://search.ebay.com/_W0QQsassZpema9 Hello All, As most of you know, a few kilos of small iron meteorites were bought in Morocco by Dean Bessey about 3 years ago. The meteorites were bought as Zagora iron meteorites but when cut and etched some of them revealed a very unusual pattern showing clearly that they were not Zagora‘s. Zagora has a different etch pattern, e.g. the Widmannstaetten lines in Zagora show a wideness of one millimeter and more, the ones in this new iron are less than 0.2 mm! This unusual iron meteorite looks similar to NWA 2680, a rare ungrouped silicated Octahedrite IAB, but this is only a visual similarity and further studies have to be done. The winning bidder will be informed as soon as we have more results. This new iron shows a stunnig pattern and is without doubt a visually very attractive meteorite. Because it is impossible to tell from the outside of the meteorite whether or not it is Zagora or the new iron, we had this metorite masterly cut (really not an easy task!), polished, etched and photographed by Marc Jost, Spacejewels, Switzerland. We have now nine small meteorite halves on ebay. Please have a look: http://search.ebay.com/_W0QQsassZpema9 Thank you, Peter BTW: There's also a small part slice of Zagami and a stunning wire brushed 1908 g Gibeon individual... MARMET-METEORITES Peter Marmet Bern, Switzerland, IMCA #2747 http://www.marmet-meteorites.com/ E-Mail: [EMAIL PROTECTED] eBay : http://search.ebay.com/_W0QQsassZpema9 __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Harper's Mag 1850 - article on meteorites
Hi, I have just uploaded pics of a nice article in Harper's for 1850 for your perusal I think I have numbered the pages in order, but I would recommend you download the images to read them anyway! http://picasaweb.google.com/Entropydave1/ thanks! Dave IMCA #0092 Sec.BIMS www.bimsociety.org __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] 65 Million-Year-Old Meteorite Traces Deep In The Ocean
http://www.russia-ic.com/education_science/science/breakthrough/450/ Meteorite Traces Deep In The Ocean Kizilova Anna Russia InfoCenter April 17, 2007 A theory suggests a giant meteorite falling on Earth 65 million years ago and killing all dinosaurs. Russian scientists have found traces of this meteorite. During a marine expedition, organized by the Institute of Marine Geology and Geophysics (Russian Academy of Sciences) and aimed at ocean studies, the crew of the science and research ship Morskoy Geofizik (Marine Geophysicist) discovered an astroblem - a circular structure, which usually forms after a celestial body falls down from the sky - at the bottom in north-west of the Pacific. Researchers gave found astroblem the name Sakhalinka. The processes that take place after celestial bodies fall into the ocean are studied very poorly, because scientists know location of very few underwater craters on our planet, and the fact that every new astroblem causes a tide of scientific interest and curiosity is not surprising at all. The Sakhalinka astroblem is unique, since it is located very deep at the ocean bottom. All known underwater craters - Chicxulub of Mexico, Mjølnir impact structure in the Barents Sea and Lockne of Sweden are located between 200 and 400 m, whereas Pacific astroblem lies as deep as 6 thousand meters. During the expedition discovered crater was investigated by means of CSP (continuous seismic profiling), thus its exact contours and some other parameters were detected. Crater's diameter at 5900 m depth is 12 km, and its depth in basement topography is 7 hundred meters. Crater's centre has following geographic coordinates - 30 degrees and 15 minutes of north latitude and 170 degrees 3 minutes of east longitude. Scientists have thought over possible conditions, which led to Sakhalinka astroblem formation, and their calculations suggest meteorite's diameter to reach 500 m. Statistics of meteorite falling claims that such large objects approach our planet only once in 100 thousand years. When such a meteorite falls into the ocean, it generates tsunamis with waves, higher than 10 m, 1 thousand km away from the epicenter, or the impact point in other words. However, no matter what a splash a giant celestial body makes, when it falls to the ocean, it forms no crater, when the ocean in the point of impact is deeper than 4 thousand meters. Therefore, Sakhalinka astroblem appeared at those times, when the ocean was much shallower than it is today. Russian think-tank has performed a reconstruction of paleooceanologic environment, which brought researchers to a conclusion that during the Cretaceous period ocean level was about 2 km lower than its current level. Sedimentary deposits, filling the astroblem, allow stating possible crater's age - the structure most likely formed between the Cretaceous and Paleogene. And then scientists have suddenly remembered the hypothesis about Earth's collision with a giant meteorite, happened some 65 million years ago. Meteorite rounded our planet from south-west to north-east and fell to many smaller meteorites, thus forming a crater belt, and finally fell somewhere to the ocean. Last trace of said celestial body on Earth scientists consider to be Kara cryptoexplosion structure. Bearing in mind movements of ocean plate in Cenozoic era, geologists think that Sakhalinka perfectly fits into the Euro-African crater belt and appeared because of said meteorite or a part of meteoritic cloud had fallen to the Earth. Everything indicates that dinosaurs were in fact killed by a giant meteorite. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Celestial Fender-Bender Left Asteroid to Cool without Insulation, Find UMass Amherst Scientists
Office of News and Information University of Massachusetts-Amherst Contact: Joseph Goldstein, 413/545-2165 April 18, 2007 #197-07 Celestial Fender-Bender Left Asteroid to Cool without Insulation, Find UMass Amherst Scientists AMHERST, Mass. -- A fender-bender between two celestial bodies that left a 200 mile-wide metallic chunk to cool in space was the likely source of a group of meteorites known as the IVA iron meteorites, suggests new research by University of Massachusetts Amherst scientists. Their findings, published in the April 19 issue of the journal Nature, help explain conflicting meteorite data that has long puzzled scientists, and sheds new light on how and when asteroids form. Jijin Yang and Joseph Goldstein of the UMass Amherst department of mechanical and industrial engineering, and Edward Scott of the Hawaii Institute of Geophysics and Planetology at the University of Hawaii at Manoa collaborated on the research. The standard model of asteroid formation says asteroidal bodies are just leftover debris from the collisions and subsequent melting that happens when planets form. Scientists find that these leftover chunks typically have a dense iron core containing nickel, surrounded by an insulating layer of silicate. Evidence has suggested that the iron-nickel core cools relatively evenly, thanks to the insulating silicate mantle. But when researchers have calculated cooling rates for the 60-odd meteorites that are known as the IVA iron meteorites (believed to have come from a single parent asteroid), they've gotten wildly different numbers, says Goldstein. We find that these cooling rates of the IVA irons vary by a factor of more than 50 and directly with the nickel content of the iron meteorite, he says. This means there's something goofy happening. Given the insulating silicate mantle, the cooling rates of the IVA irons ought to have been very similar, he says. So Goldstein and his colleagues re-calculated cooling rates for 10 IVA irons and combined the data with computer model simulations. They also examined the microstructure of several of the irons using a transmission electron microscope. The IVA meteorites must have cooled as one, big chunk, roughly 200 miles-wide and without an insulating mantle, the scientists conclude, not in the form of a smaller insulated body as had previously been thought. If correct, the parent asteroid would have been comparable in size to the largest M class asteroid, 6 Psyche, says the research team. You can see the same phenomenon occurring when cooling steel, explains Goldstein. If you take a new piece of steel out of a huge blast furnace and set it down, we know that the outside cools a lot faster than the inside because there's no insulation. The same would be true of the IVA irons in a metallic asteroid. Roughly 60 meteorites retrieved from around the world have the chemical makeup of the IVA irons, suggesting that they were all part of one metallic asteroid that broke up about 450 million years ago and then fell to earth in pieces. Scientists have proposed several theories over the decades to rationalize the varying cooling rates seen in IVA meteorites. One is that either the data or the computer simulations are faulty. There's the Rubble-Pile model, which posits that various pieces of the asteroid broke off at some point and then were thrown back together by influences such as gravity and centrifugal force. Another model, the so-called Raisin Bread effect, explains the various cooling rates by picturing various metal chunks spread throughout the silicate mantel of the asteroid. None however, could explain why the cooling rates vary directly with the nickel content of the meteorites. Now the researchers think the IVA irons' parent asteroid must have formed after two protoplanets sideswiped each other, thus breaking off many different pieces with varying amounts of silicate. The authors believe that the metal containing the IVA irons was one of these pieces that contained little or no silicate insulation. Our study was created to understand how the asteroid was formed almost one million years after the formation of the solar system, says Yang. Our theory explains the different cooling rates as part of a comprehensive description of the formation of the asteroid containing the IVA irons. IMAGE CAPTION: [http://www.newswise.com/images/uploads/2007/04/17/fullsize/Carlton_Meteorite_1.jpg (61KB)] Scientists analyze certain patterns in meteorites, such as those in this Carlton Meteorite, to obtain the cooling rates of asteroids. (J. Goldstein, UMass Amherst and H. Yakowitz, NIST) __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Celestial Fender-Bender Left Asteroid To Cool Without Insulation
Note: Asteroid #6 of course is 6 Hebe, the most frequently mentioned possible H chondrite Parent Body. Hebe is easy to see in binoculars. Much dimmer and metallic 16 Psyche just passed opposition when it was ideal for viewing last month and still can be seen if you have a medium scope. -Doug http://www.sciencedaily.com/releases/2007/04/070418141027.htm Celestial Fender-Bender Left Asteroid To Cool Without Insulation Science Daily — A fender-bender between two celestial bodies that left a 200 mile-wide metallic chunk to cool in space was the likely source of a group of meteorites known as the IVA iron meteorites, suggests new research by University of Massachusetts Amherst scientists. Their findings, published in the April 19 issue of the journal Nature, help explain conflicting meteorite data that has long puzzled scientists, and sheds new light on how and when asteroids form. (Image) Scientists analyze certain patterns in meteorites, such as those in this Carlton Meteorite, to obtain the cooling rates of asteroids. (Credit: J Goldstein UMass Amherst, and H. Yakowitz, NIST) Jijin Yang and Joseph Goldstein of the UMass Amherst department of mechanical and industrial engineering, and Edward Scott of the Hawaii Institute of Geophysics and Planetology at the University of Hawaii at Manoa collaborated on the research. The standard model of asteroid formation says asteroidal bodies are just leftover debris from the collisions and subsequent melting that happens when planets form. Scientists find that these leftover chunks typically have a dense iron core containing nickel, surrounded by an insulating layer of silicate. Evidence has suggested that the iron-nickel core cools relatively evenly, thanks to the insulating silicate mantle. But when researchers have calculated cooling rates for the 60-odd meteorites that are known as the IVA iron meteorites (believed to have come from a single parent asteroid), they’ve gotten wildly different numbers, says Goldstein. “We find that these cooling rates of the IVA irons vary by a factor of more than 50 and directly with the nickel content of the iron meteorite,” he says. “This means there’s something goofy happening.” Given the insulating silicate mantle, the cooling rates of the IVA irons ought to have been very similar, he says. So Goldstein and his colleagues re-calculated cooling rates for 10 IVA irons and combined the data with computer model simulations. They also examined the microstructure of several of the irons using a transmission electron microscope. The IVA meteorites must have cooled as one, big chunk, roughly 200 miles-wide and without an insulating mantle, the scientists conclude, not in the form of a smaller insulated body as had previously been thought. If correct, the parent asteroid would have been comparable in size to the largest M class asteroid, 6 Psyche, says the research team. “You can see the same phenomenon occurring when cooling steel,” explains Goldstein. “If you take a new piece of steel out of a huge blast furnace and set it down, we know that the outside cools a lot faster than the inside because there’s no insulation. The same would be true of the IVA irons in a metallic asteroid.” Roughly 60 meteorites retrieved from around the world have the chemical makeup of the IVA irons, suggesting that they were all part of one metallic asteroid that broke up about 450 million years ago and then fell to earth in pieces. Scientists have proposed several theories over the decades to rationalize the varying cooling rates seen in IVA meteorites. One is that either the data or the computer simulations are faulty. There’s the “Rubble-Pile” model, which posits that various pieces of the asteroid broke off at some point and then were thrown back together by influences such as gravity and centrifugal force. Another model, the so-called “Raisin Bread” effect, explains the various cooling rates by picturing various metal chunks spread throughout the silicate mantel of the asteroid. None however, could explain why the cooling rates vary directly with the nickel content of the meteorites. Now the researchers think the IVA irons’ parent asteroid must have formed after two protoplanets sideswiped each other, thus breaking off many different pieces with varying amounts of silicate. The authors believe that the metal containing the IVA irons was one of these pieces that contained little or no silicate insulation. “Our study was created to understand how the asteroid was formed almost one million years after the formation of the solar system,” says Yang. “Our theory explains the different cooling rates as part of a comprehensive description of the formation of the asteroid containing the IVA irons.” Note: This story has been adapted from a news release issued by University of Massachusetts Amherst. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com
Re: [meteorite-list] Angrite NWA 4590 auctions have ended now, ...
In a message dated 4/18/2007 12:49:41 P.M. Mountain Standard Time, [EMAIL PROTECTED] writes: I received mine (1.024 grams) today. It sports patches of shiny, glossy fusion crust today and it is a pleasure to hold and a feast for the eyes to behold! Wish I had a thin section of this gorgeous plutonic angrite. Best wishes, Angritically, Bernd __ Glad to hear that you like it, Bernd. Would you like me to reserve a Thin-Section for you? Obviously it will take a while, but I am getting them made by our favorite expert. Anyone else? Anne M. Black www.IMPACTIKA.com [EMAIL PROTECTED] President, I.M.C.A. Inc. www.IMCA.cc ** See what's free at http://www.aol.com. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Selling my Gold Bug 2 !
Hi All, I'm selling my Gold Bug 2. It's about 2 years old and is the same one that I used in the Cash and Treasures TV show. It is well used but not abused and still works perfectly. I don't have the manual but am including a brand new set of batteries. This is one of the best meteorite detectors around! The first $425.00 takes it. Add $15.00 shipping in the USA. Take a look at the pictures. http://new.photos.yahoo.com/meteoritemall/album/576460762398551665 Paypal is fine to [EMAIL PROTECTED] Thanks, Ruben __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] SAU Specimen
Hi All, I have a question to put out. I recently have been reorganizing my micro collection to catalog. I ran across a gem jar with a small 2.23g crusted fragment marked SaU 119. I didn't really think much of it at first, but when I looked up the information on it I realized this could bn an issue. How likely is it to have a 2.23g crusted fragment of a meteorite with a TKW of 432gms from a single stone with most of the mass in Russian Institutions? I bought this piece a couple of years ago on Ebay and no longer have a specimen card, if I ever did. I don't remember who I bought it from. Any thoughts? CJ Lebel #3432 Nothing in life is to be feared. It is only to be understood ... _ Dont quit your job Take Classes Online and Earn your Degree in 1 year. Start Today! http://www.classesusa.com/clickcount.cfm?id=866146goto=http%3A%2F%2Fwww.classesusa.com%2Ffeaturedschools%2Fonlinedegreesmp%2Fform-dyn1.html%3Fsplovr%3D866144 __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] SAU Specimen
Hi All, Problem solved, Thanks! Cj Nothing in life is to be feared. It is only to be understood ... _ Get a FREE Web site, company branded e-mail and more from Microsoft Office Live! http://clk.atdmt.com/MRT/go/mcrssaub0050001411mrt/direct/01/ __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Harper's Mag 1850 - article on meteorites
Hi, Dave, Thanks for the Blast From The Past! I expected most of the things I found there, the Great Leonids of 1833, L'Aigle, and so forth, but there was one thing completely new to me: the determination of the height of meteors by Brandes and Benzenberg (while still students!) in 1798, using long base-line observations by coordinated observers to triangulate meteor altitude by parallax. I had never heard of this being done so early, and it's a damned clever technique. I Googled the clever students and found: http://www.worldwideschool.org/library/books/sci/history/AHistoryofScienceVolumeIII/chap36.html I found whole story at: http://www.lpi.usra.edu/meetings/metsoc2000/pdf/5008.pdf Brandes and Benzenberg's professor, one Lichtenberg, set them up in the experiment to measure the exact height of meteors. They chose a baseline suitable to measure a meteor height of ONE mile, because meteors were believed to be an atmospheric phenomenon, like lightning. I mean, Aristole said so! Must be right... Lichtenberg wobbled back and forth between Aristole and Chladni, so he did what any good scientist would do -- he sent some grad students out into the fall weather to freeze their butts off all night gathering data! It was immediately obvious that their baseline was too short and that the meteors were much higher than one mile. Eventually, they used a 15,625 meter baseline and observed meteors as high as from 30 km altitude up to 170 kilometers, moving at speeds of 30 to 44 km/s, remarkably consistent with what we know today. At any rate, it seems to me a remarkable achievement for the time and I was surprised to have never heard of it (maybe it's just me). They published their results in 1800, but apparently other scientists did not know how to interpret the results, and it was not until about 1830 that they were well understood. Thanks again, Dave. Sterling --- - Original Message - From: Dave Harris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: metlist meteorite-list@meteoritecentral.com Sent: Wednesday, April 18, 2007 4:46 PM Subject: [meteorite-list] Harper's Mag 1850 - article on meteorites Hi, I have just uploaded pics of a nice article in Harper's for 1850 for your perusal I think I have numbered the pages in order, but I would recommend you download the images to read them anyway! http://picasaweb.google.com/Entropydave1/ thanks! Dave IMCA #0092 Sec.BIMS www.bimsociety.org __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
