[meteorite-list] How is Tucson Going??
Hi List! I have not heard much about Tucson this year. Not much in the way of people sharing anything. So what's going on there for the show? Any killer buys? What are the prices looking like? Everyone loose their butts or what? Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How is Tucson Going??
Show is not open, perhaps that's why you're not hearing much. Setup just starting. I move into my room tomorrow and will be open by Tuesday/Wednesday. Michael Farmer Sent from my iPhone On Jan 25, 2014, at 4:54 AM, Jim Wooddell jim.woodd...@suddenlink.net wrote: Hi List! I have not heard much about Tucson this year. Not much in the way of people sharing anything. So what's going on there for the show? Any killer buys? What are the prices looking like? Everyone loose their butts or what? Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How is Tucson Going?? Astronomy Event
Hi Jim: From a local, I am looking forward to seeing old friends and other locals who I do not see very often. By Saturday February 1, it will have cooled down to a high of 71 (it may hit 80 at the end of the month) and there is a small chance of rain (should we blame those Colorado folks who will be arriving around then?). Also, if you have a car and free time, on Saturday February 8, at Pima Community College East Campus (near Davis Monthan Air Force Base) there will be an all-day astronomy expo and evening observing (if it is clear) hosted by Astronomy Magazine. I will be there (for Girl Scouts, Planetary Science Institute, and James Webb Telescope) and the Tucson Amateur Astronomy Association and people from OSIRIS-REx will be there, too. http://cs.astronomy.com/asy/b/daves-universe/archive/2014/01/16/gearing-up-for-our-big-tucson-star-party.aspx Larry Hi List! I have not heard much about Tucson this year. Not much in the way of people sharing anything. So what's going on there for the show? Any killer buys? What are the prices looking like? Everyone loose their butts or what? Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] friction or ram pressure?
Hi all! I have a question for you regarding falling stars and fireballs! Which is the physical process that heats a meteoroid during his travel through the atmosphere? Is the friction with the air molecules or the ram pressure of the shock wave in front of the meteoroid? I think, but maybe I'm wrong: for the smaller meteoroids like the one that generate the falling stars the main process is the friction, instead for the bigger meteoroid like the one that generate meteorite on the ground or for example for a Space Ship like the Space Shuttle the main process is the ram pressure ... I'm right? Thanks a lot!!! x Francesco __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] friction or ram pressure?
Your understanding is broadly correct, although I don't think friction is quite the right word to describe the heating process for particles smaller than about a centimeter. The mechanism of heating depends on the particle size and on the mean free path of atmospheric molecules (and therefore on height). For centimeter scale particles, most of the heating is the result of creating a compressed gas zone along the leading edge. For millimeter scale particles the heating involves collisional processes. Not surprisingly, there's an intermediate range where both processes are operating. Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 1/25/2014 7:54 AM, Francesco Moser wrote: Hi all! I have a question for you regarding falling stars and fireballs! Which is the physical process that heats a meteoroid during his travel through the atmosphere? Is the friction with the air molecules or the ram pressure of the shock wave in front of the meteoroid? I think, but maybe I'm wrong: for the smaller meteoroids like the one that generate the falling stars the main process is the friction, instead for the bigger meteoroid like the one that generate meteorite on the ground or for example for a Space Ship like the Space Shuttle the main process is the ram pressure ... I'm right? Thanks a lot!!! x Francesco __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD: Over 200 New Specimens Added Sale
Hello, It has been a long time since I have offered anything - I have listed over 200 new specimens in my ebay store, plus a sale is on right now! Thanks, Michael Cottingham ALL SALE ITEMS HERE: http://stores.ebay.com/voyage-botanica-natural-history __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD: Over 200 New Specimens Added Sale
Hello, It has been a long time since I have offered anything - I have listed over 200 new specimens in my ebay store, plus a sale is on right now! Thanks, Michael Cottingham ALL SALE ITEMS HERE: http://stores.ebay.com/voyage-botanica-natural-history __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD: AD: Over 200 New Specimens Added Sale
Hello, It has been a long time since I have offered anything - I have listed over 200 new specimens in my ebay store, plus a sale is on right now! Thanks, Michael Cottingham ALL SALE ITEMS HERE: http://stores.ebay.com/voyage-botanica-natural-history __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD - Ebay Auctions Ending soon
Dear List Members, i have some auctions at Ebay ending tomorrow. At the moment they have all low bids. Take a look here: http://www.ebay.com/sch/gipometeorite/m.html?item=171224133227ssPageName=ADME%3AL%3ALCA%3AUS%3A1123rt=nc_trksid=p2047675.l2562 Many thanks for viewing, Carsten Giessler __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] R: friction or ram pressure?
Thanks for your kind answer! So we can say: meteoroids dimensions: ~1cm friction ~1cm ram pressure But I have still a question... how the ablation process works on the bigger meteoroids? The ram pressure heats the air, the hot air heats the front surface of the meteoroid to the fusion/sublimation temperature, right? But is the collisional process that create oriented shape, ragmaglipts, flow line ... or what else process?? Thanks x Francesco -Messaggio originale- Da: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] Per conto di Chris Peterson Inviato: sabato 25 gennaio 2014 16:24 A: meteorite-list@meteoritecentral.com Oggetto: Re: [meteorite-list] friction or ram pressure? Your understanding is broadly correct, although I don't think friction is quite the right word to describe the heating process for particles smaller than about a centimeter. The mechanism of heating depends on the particle size and on the mean free path of atmospheric molecules (and therefore on height). For centimeter scale particles, most of the heating is the result of creating a compressed gas zone along the leading edge. For millimeter scale particles the heating involves collisional processes. Not surprisingly, there's an intermediate range where both processes are operating. Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 1/25/2014 7:54 AM, Francesco Moser wrote: Hi all! I have a question for you regarding falling stars and fireballs! Which is the physical process that heats a meteoroid during his travel through the atmosphere? Is the friction with the air molecules or the ram pressure of the shock wave in front of the meteoroid? I think, but maybe I'm wrong: for the smaller meteoroids like the one that generate the falling stars the main process is the friction, instead for the bigger meteoroid like the one that generate meteorite on the ground or for example for a Space Ship like the Space Shuttle the main process is the ram pressure ... I'm right? Thanks a lot!!! x Francesco __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] AD: 24 hours sale - Chelyabinsk Impact Melt - CV3 - NWA xxxx and much more
Dear List Members, I have listed on ebay some new offers. 24 hours sale only! Auctions start today and ending tomorrow. The pieces starts by $1.99 without reserve price. All auctions you can find here: http://stores.ebay.com/Mirko-Graul-Meteorite/_i.html?rt=ncLH_Auction=1_sc=1_sid=18192829_sop=1_trksid=p4634.c0.m309 and all my 137 offers you can find here: http://stores.ebay.com/Mirko-Graul-Meteorite/_i.html?rt=nc_sc=1_sid=18192829_sticky=1_trksid=p4634.c0.m14_sop=12_sc=1 Best regards Mirko Mirko Graul Meteorite Quittenring.4 16321 Bernau GERMANY Phone: 0049-1724105015 E-Mail: m_gr...@yahoo.de WEB: www.meteorite-mirko.de Member of The Meteoritical Society (International Society for Meteoritics and Planetery Science) IMCA-Member: 2113 (International Meteorite Collectors Association) __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] R: friction or ram pressure?
Hi, all, the hot air heats the front surface of the meteoroid... That's where the complexity is hiding. The rammed air jacket is hotter the deeper you get into it. The layer closest to the meteoroid is the hottest, achieving the plasma state and temperatures --- 30,000F to 50,000F. Plasma does not heat anything much by contact. Instead, plasma at those temperatures transfer heat by radiation. The rammed air layers ahead are converted to plasma by radiation until all but the outermost layer of the jacket is plasma. The technical term for this jacket is the meteor head. On the inner side of the meteor head, the plasma transfers heat to the meteoroid, by radiation. The spectrum of 30,000F plasma runs from long radio waves to soft x-rays. (You can Google up how to listen to meteors by radio.) It's the other end of the spectrum that has the most powerful effect on meteoroid rock. Soft x-rays can boil rock 10,000 times faster than your microwave can overcook a chicken pot pie. Areas of lower boiling point get excavated faster, forming regmaglypts. Regmaglypts are also caused by the irregularities in the meteoroid's shape which affect the meteor head's shape. Between the plasma and the rock face there is little heat transferred by conduction. Radiative transfer is the predominant mechanism. Rock plasma and atmospheric plasma mix as the plasma escapes by moving from the center of the meteoroid face back 90 degrees to the point where it can be shed into the trail, combining as the plasma cools to the point where atoms CAN combine into meteoritic dust. They can be seen as areas of the trail just behind the meteoroid described as burning. There is little physical contact between the meteoroid and the plasma in our usual sense; hot as it is, it's not very dense by Earthly standards, just more dense than the atmosphere at 60 miles altitude. But, it's just 5 or 10 times hotter than the surface of the Sun. That does the trick very nicely. Friction is not really an adequate term for the heating mechanism. Assuming a generally spherical shape for the meteoroid, to travel back half the meteoroid's diameter to reach the point where the tail detaches it must traverse a distance of 0.78 the meteoroid's diameter, hence, there must be a radial plasma wind accelerating across the face of the meteoroid to a velocity 57% greater than that of the meteoroid itself. We assume this is responsible for the flow lines. Here's some more (technical) information for those more fascinated. First, an excellent general summary of radar studies of meteor heads and trails here: http://www.cas.uio.no/Publications/Seminar/Convergence_Dyrud.pdf More technical treatments here: http://www.atmos-chem-phys.net/4/817/2004/acp-4-817-2004.pdf and here: http://ftp.rta.nato.int/public/PubFullText/RTO/MP/RTO-MP-IST-056/MP-IST-056- 12.pdf and then there's this tome (seriously; it's a book!): http://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=1177context=etd A lot of this stuff is hotly debated. How many tons of meteors are delivered to Earth every year? They're fighting over that. How many meteors a year? Fighting. And so on. Enjoy. Sterling K. Webb -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Francesco Moser Sent: Saturday, January 25, 2014 1:22 PM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] R: friction or ram pressure? Thanks for your kind answer! So we can say: meteoroids dimensions: ~1cm friction ~1cm ram pressure But I have still a question... how the ablation process works on the bigger meteoroids? The ram pressure heats the air, the hot air heats the front surface of the meteoroid to the fusion/sublimation temperature, right? But is the collisional process that create oriented shape, ragmaglipts, flow line ... or what else process?? Thanks x Francesco -Messaggio originale- Da: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] Per conto di Chris Peterson Inviato: sabato 25 gennaio 2014 16:24 A: meteorite-list@meteoritecentral.com Oggetto: Re: [meteorite-list] friction or ram pressure? Your understanding is broadly correct, although I don't think friction is quite the right word to describe the heating process for particles smaller than about a centimeter. The mechanism of heating depends on the particle size and on the mean free path of atmospheric molecules (and therefore on height). For centimeter scale particles, most of the heating is the result of creating a compressed gas zone along the leading edge. For millimeter scale particles the heating involves collisional processes. Not surprisingly, there's an intermediate range where both processes are operating. Chris *** Chris L Peterson Cloudbait Observatory
[meteorite-list] China's Moon Rover Has A Mechanical Control Anomaly
http://news.xinhuanet.com/english/china/2014-01/25/c_133072966.htm China's moon rover monitored with abnormity English.news.cn January 25, 2014 BEIJING, Jan. 25 (Xinhua) -- China's moon rover Yutu (Jade Rabbit) has had a mechanical control abnormity, and scientists are organizing an overhaul. The abnormity occurred due to the complicated lunar surface environment, the State Administration of Science, Technology and Industry for National Defence (SASTIND) said on Saturday, without giving further details. The abnormity emerged before the rover went into its second dormancy at dawn on Saturday as the lunar night fell again, according to the SASTIND. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteorite Picture of the Day
Today's Meteorite Picture of the Day: Tridymite Contributed by: Anne Black http://www.tucsonmeteorites.com/mpodmain.asp __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] BC Meteorites - Tucson Show Location + AD: $0.01 eBay Auctions Ending
Good Day List! With much excitement, I am happy to announce I will be returning for my second year as a dealer at the Tucson Gem and Mineral Show. I am also happy to inform I have moved and will now be located at the Hotel Tucson City Center(HTCC) formally the Inn Suites as most of us still refer to it. You can find myself and all of our favorite celestial visitors in room #250. Many new goodies for the viewing and purchasing pleasure, including all that remains of the breathtaking meteorite NWA 7731 L3.00 - the most primitive planetary material to ever be offered on the market! My favorite part of doing these shows is meeting all of you face to face, I encourage everyone to stop in! BC Meteorites Hotel Tucson City Center #250 475 N Granada Ave Tucson, AZ 85701 February 1-15, 2014 I have over 90 items on eBay ending soon, 2 dozen of which started at $0.01 including large full slices of some EXTREMELY rare material and SUPER ORIENTED Sikhote-Alin's - all at killer deals http://www.ebay.com/sch/bc-meteorites/m All the best! Adam Bates www.bcmeteorites.com __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
