Re: [meteorite-list] Meteor shower meteorite dropping events
Chris, Eric, List, Mazapil is a very old argument, indeed. Take a look at: http://articles.adsabs.harvard.edu/full/2002M%26PS...37..649B or the same at the author's website: http://hyperion.cc.uregina.ca/~astro/Mazapil.pdf and this one: http://www.lpi.usra.edu/meetings/lpsc1987/pdf/1377.pdf Personally, the idea that comets drop iron meteorites is silly. The fact that this is the one and only example, out of thousands of falls, of the coinciding of a meteorite fall with a meteor shower suggests to me that when you flip coins often enough, a coin will land on its edge. Sterling K. Webb --- - Original Message - From: Meteorites USA e...@meteoritesusa.com To: meteorite-list@meteoritecentral.com Sent: Wednesday, August 11, 2010 11:34 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hello Chris, Eric, The simple answer is no. No meteorites have ever been found that match all criteria for what we believe cometary material should look like. http://www.lpi.usra.edu/meetings/LPSC98/pdf/1004.pdf This is also the sort of topic that has been brought up again and again on the list. While I couldn't find any direct references for some reason, I was able to turn these up: http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg84604.html http://six.pairlist.net/pipermail/meteorite-list/2004-May/000683.html To condense: a few meteorites, namely the CI's, come close to what we think cometary material might look like. But those meteorites weren't associated with any known meteor showers, and are likely just fragments of D-class asteroids, which may or may not be remnants of burned-out comets (comets that got trapped in the inner solar system and stripped of most of their volatiles). But, based on the above paper, even the CI's are probably not actual cometary material, though they fit the bill better than most other meteorites, for sure. Suggesting that an iron meteorite like Mazapil might be associated with a comet is nigh on preposterous - comets aren't made of iron, and shouldn't have anything to do with such a meteorite. Comets are undifferentiated bodies that have generally remained icy since their formation over four and a half billion years ago. A two or three billion year old iron with a thompson structure that took the better part of a billion years to form simply could not be from a comet. http://adsabs.harvard.edu/abs/2002M%26PS...37..649B Some more basic reading: http://www.amsmeteors.org/faqm.html#11 Scroll to section before bottom: Meteorites from Comets? http://www.pibburns.com/catastro/meteors.htm Best, Jason On Wed, Aug 11, 2010 at 9:34 PM, Meteorites USA e...@meteoritesusa.com wrote: Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Haha, but Sterling -- I'd like to refer you to one of the posts (one of yours!) I linked to in my reply: http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg84604.html The Wisconsin fall was another coincidence -- and it's not the only one. If you go through the fall calendars, more than a few meteorites have fallen on dates that coincide with known meteor showers. This is especially true if you take into account the fact that showers often produce meteors for weeks leading up to, and away from their peaks. Mazapil was deemed particularly interesting because it fell during a very strong outburst of activity from the shower with which it is associated. Granted, I'm in no way advocating the cometary origin of any meteorites. It's simply the result of the frequency of meteor showers and the frequency with which unrelated meteoric material reaches the earth...but it has happened more than once. Regards, Jason On Wed, Aug 11, 2010 at 11:01 PM, Sterling K. Webb sterling_k_w...@sbcglobal.net wrote: Chris, Eric, List, Mazapil is a very old argument, indeed. Take a look at: http://articles.adsabs.harvard.edu/full/2002M%26PS...37..649B or the same at the author's website: http://hyperion.cc.uregina.ca/~astro/Mazapil.pdf and this one: http://www.lpi.usra.edu/meetings/lpsc1987/pdf/1377.pdf Personally, the idea that comets drop iron meteorites is silly. The fact that this is the one and only example, out of thousands of falls, of the coinciding of a meteorite fall with a meteor shower suggests to me that when you flip coins often enough, a coin will land on its edge. Sterling K. Webb --- - Original Message - From: Meteorites USA e...@meteoritesusa.com To: meteorite-list@meteoritecentral.com Sent: Wednesday, August 11, 2010 11:34 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hi Chris, There are many, many meteorites that fell during meteor showers as showers happen on a regular basis,e.g. Gemenids, Leonids, Persieds etc. etc. but that does not mean to say that the meteorite fall had any association with the shower. Graham, UK On 12 August 2010 04:59, Chris Spratt cspr...@islandnet.com wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hi, Jason, Chris, Eric, List, Now, I'm going to turn around and play Devil's Advocate and ridicule my own ridicule. Of course the iron Mazapil came from the Andromedid stream! Here's a good paper on the Andromedids and their parent body, Comet 3D/Biela: http://authors.library.caltech.edu/12800/1/JENaj07b.pdf From it, we learn that Comet 3D/Biela is a disintegrating comet that broke into two pieces at aphelion in 1842/43, but was trailing fragments both before and after that event. It is the source of the Andromedids, one of six comets associated with an annual meteor shower. The previous paper I cited, by Martin Beech, calculated the original size and mass of Mazapil, assuming it was in the Andromedid orbit and moving with the dust swarm, that is, had the same radiant and velocity as an Andromedid. It would have been a one-meter plus iron body of about 100 tons mass. The two pieces of 3D/Biela (called imaginatively enough, A and B) were observed the last time in 1852. A big search for A and B at the 1865/66 return of Biela failed to discover them. In the nineteenth century, comets were considered to be rubble piles anyway and even now, we think of them as weak and unconsolidated, so no one is surprised it vanished. The Andromedids were always a weak shower (a few hundred per hour) but after Biela's breakup, they started to put on big shows. In 1885, 15,000 meteors per hour! Obviously, there was a lot more material in the stream after the 1842 breakup and the Earth cut through a denser portion of that stream. Because we think of comets as inherently weak, we assign the breakup no other cause than that the comet was merely falling apart, like an old house collapsing, but what if it was hit by a 100-ton iron meteoroid? Biela has plenty of mass (10,000,000 tons) but a 100-ton fast impactor could do a lot of damage to a weak object, even one a million times heavier, if it hit it just right. Maybe fracture it into two pieces? The 100-ton chunk of iron would be completely undamaged by hitting a weak object, no matter how massive. It would dig into it, might even bore right through it, or suffer multiple collisions with the bigger cometary fragments of its own impact. A series of battering, uneven impacts with a disintegrating comet could steal away most of the kinetic energy of the iron wrecking ball. In fact, if the impact brought it to a relatively low energy of motion, the impactor would lose all of its vector. It would be what's called an inelastic collision. The mostly undamaged iron object would simply fall in and move on the same vector as the big mass it had hit, thus sharing its orbit. One basic rule of physics is that if you can do it with billiard balls, it can probably happen in the real world! If you drive a billiard ball at high speed into the belly of (very) giant plush teddy bear, it will not bounce away with much energy. It will nearly stop. And if the impactor, whatever its previous orbit was, fell into the Biela orbit, it could easily have been unfortunate enough to encounter the Earth in its path, as did the 100,000+ other fragments of Biela in 1885. If you have an iron meteorite that fell as part of an annual meteor shower, you pick it up and say, What's YOUR story, little rock? Improbable? Unlikely? A one-in-a-million chance? In a solar system 4.5 billion years old, a one-in-a-million chance means it's already happened 4500 times. Sterling K. Webb -- Footnote from paper above: If the bigger lost fragment A survives, it may be now hiding as a dormant comet. If so, K. Kinoshita calculated a particularly good encounter in 2010, when the dormant comet is expected to pass Earth at only 0.13 AU on November 3.25, following a close encounter with Jupiter (0.79AU) on 2009 March 13.5. Maybe an NEA hunt or WISE will find it. --- - Original Message - From: Jason Utas meteorite...@gmail.com To: Sterling K. Webb sterling_k_w...@sbcglobal.net; Meteorite-list meteorite-list@meteoritecentral.com Sent: Thursday, August 12, 2010 1:20 AM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Haha, but Sterling -- I'd like to refer you to one of the posts (one of yours!) I linked to in my reply: http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg84604.html The Wisconsin fall was another coincidence -- and it's not the only one. If you go through the fall calendars, more than a few meteorites have fallen on dates that coincide with known meteor showers. This is especially true if you take into account the fact that showers often produce meteors for weeks leading up to, and away from their peaks. Mazapil was deemed particularly interesting because it fell during a very strong outburst of activity from the shower with which it is associated. Granted, I'm in no way advocating
Re: [meteorite-list] Meteor shower meteorite dropping events
I remember when the first results from the Stardust mission were coming out. Everyone was surprised to see the the CI chondrites did not match as well as first thought and that the best match were the metal-rich CH chondrites. I'm not sure what the studies have shown since then but maybe someone else here knows of recent papers? Cheers, Jeff - Original Message - From: Sterling K. Webb sterling_k_w...@sbcglobal.net To: meteorite-list@meteoritecentral.com Cc: cspr...@islandnet.com Sent: Thursday, August 12, 2010 4:01 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Chris, Eric, List, Mazapil is a very old argument, indeed. Take a look at: http://articles.adsabs.harvard.edu/full/2002M%26PS...37..649B or the same at the author's website: http://hyperion.cc.uregina.ca/~astro/Mazapil.pdf and this one: http://www.lpi.usra.edu/meetings/lpsc1987/pdf/1377.pdf Personally, the idea that comets drop iron meteorites is silly. The fact that this is the one and only example, out of thousands of falls, of the coinciding of a meteorite fall with a meteor shower suggests to me that when you flip coins often enough, a coin will land on its edge. Sterling K. Webb --- - Original Message - From: Meteorites USA e...@meteoritesusa.com To: meteorite-list@meteoritecentral.com Sent: Wednesday, August 11, 2010 11:34 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Jeff: Why would you expect cometary dust particles to look like CIs. CIs are aqueously altered, and there is little indication that this would happen on a comet (though there were possible observations of this from some Deep Impact observations). You need a good deal of heating, enough to melt ice so that the water can alter the silicates. Interplanetary Dust Particles (IDPs) which are found mostly high in the atmosphere, are not aqueously altered and are thought to be derived from comets. Larry I remember when the first results from the Stardust mission were coming out. Everyone was surprised to see the the CI chondrites did not match as well as first thought and that the best match were the metal-rich CH chondrites. I'm not sure what the studies have shown since then but maybe someone else here knows of recent papers? Cheers, Jeff - Original Message - From: Sterling K. Webb sterling_k_w...@sbcglobal.net To: meteorite-list@meteoritecentral.com Cc: cspr...@islandnet.com Sent: Thursday, August 12, 2010 4:01 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Chris, Eric, List, Mazapil is a very old argument, indeed. Take a look at: http://articles.adsabs.harvard.edu/full/2002M%26PS...37..649B or the same at the author's website: http://hyperion.cc.uregina.ca/~astro/Mazapil.pdf and this one: http://www.lpi.usra.edu/meetings/lpsc1987/pdf/1377.pdf Personally, the idea that comets drop iron meteorites is silly. The fact that this is the one and only example, out of thousands of falls, of the coinciding of a meteorite fall with a meteor shower suggests to me that when you flip coins often enough, a coin will land on its edge. Sterling K. Webb --- - Original Message - From: Meteorites USA e...@meteoritesusa.com To: meteorite-list@meteoritecentral.com Sent: Wednesday, August 11, 2010 11:34 PM Subject: Re: [meteorite-list] Meteor shower meteorite dropping events Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hi List: Sterling K Webb mentioned this paper about 3/DBiela Here's a good paper on the Andromedids and their parent body, Comet 3D/Biela: http://authors.library.caltech.edu/12800/1/JENaj07b.pdf I see that one of my earlier essays on this comet was cited. I'd forgotten about that paper. Thanks. I wonder if any small sample of Mazapil are available for private collectors? Chris. Spratt Victoria, BC __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hi Sterling. Eric. Jason and all. IN Cosmic billiards nearly anything is possible. IF A 22 Bullit can cause an orange to flip upside down or spin. A large enough impact could also flip or spinn the earth. And its size would not have to be in the current range of an extinction event impactor. An meteor with enough mass hitting near either pole could cause a flip or change the orientation of the earth enough to cause an climatic disaster resulting in mass extinctions. The smaller masses currently considered to be not a threat could in reality cause a chain of events resulting in mass extinction. A meteorite a mile across might not be an extinction event if it impacts at the equator. But if it hits near either pole the results would be the same as if a larger impactor of 20miles across hit the equator or worse. I hope it never happens! Steve __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteor Shower Meteorite dropping events (Mazapil: a repost - original post Sep 15, 2004)
Hi All, BEECH Martin (2002) The Mazapil meteorite: From paradigm to periphery (MAPS 37-5, 2002 May, pp. 649-660). . and, of course, there is the unsurpassable Vagn Buchwald: BUCHWALD, V.F. (1975) Handbook of Iron Meteorites, Volume 2, pp. 808-813. Some more pertinent references: HIDDEN W.E. (1887) On the Mazapil meteoric iron, which fell November 27th, 1885 (Am. J. Sci. 33, pp. 221-226). HARVEY A. (1904) Shooting stars versus uranoliths with special reference to the Mazapil (Mexico) meteorite (Selected Papers and Proceedings of the Royal Astronomical Society of Canada, ed. A. Harvey, pp. 30-51, Z.M. Collins, Toronto, Canada). WYLIE C.C. (1933) The temperature of the Mazapil meteorite (Popular Astronomy 41, pp. 408-410). Best wishes, Bernd __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteor shower meteorite dropping events
I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Hi Chris and all, I'm sure your aware of the relationship of meteors vs fireball events working on trying to photograph them. For those less familiar, and my thoughts regarding these events, meteor showers are associated with comets and are the trailing debris behind the comet. When the earth enters an orbit of a comet we usually have some sort of meteor shower. This material is very fine and it doesn't take much to make a nice streak in our atmosphere. Could there be chunks of heavier material, there could be. As we send space craft out to various comets we should have a better idea of composition and if stony or iron material is present. Since comets formed out in the far reaches of our solar system the materials making up comets should be fine icy particles. Fireball events that drop meteorites are normally coming from collisions in the asteroid belt where the meteoriods make their way into the inner solar system. Now commenting on the possibility of an iron meteorite falling from a meteor shower, while it can't be ruled out completely, most likely the iron just happen to fall during the shower and isn't related to the cometary debris or comet. A chance happening during the shower that gives the illusion that it fell as part of the debris. It would be hard to prove it one way or the other, unless a good set of photographs or expert whitnesses could plot an orbit showing it to be a part of the shower. I'm incline to think it was unrelated. Certain carbonaceous meteorites have been suggested to be cometary debris. The friable nature of the material would make survival of this material rare. I would guess it would have to be material that has to catch up with the Earth and fall at lower speeds in order to survive the fall. I believe that we still lack any absolute evidence of any material coming from meteor showers at this point. Meteorites fall randomly and it isn't impossible for them to fall during a meteor shower, unrelated to the shower event. Best! --AL Mitterling Quoting Chris Spratt cspr...@islandnet.com: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor shower meteorite dropping events
Thanks for the links Jason! Eric On 8/11/2010 10:18 PM, Jason Utas wrote: Hello Chris, Eric, The simple answer is no. No meteorites have ever been found that match all criteria for what we believe cometary material should look like. http://www.lpi.usra.edu/meetings/LPSC98/pdf/1004.pdf This is also the sort of topic that has been brought up again and again on the list. While I couldn't find any direct references for some reason, I was able to turn these up: http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg84604.html http://six.pairlist.net/pipermail/meteorite-list/2004-May/000683.html To condense: a few meteorites, namely the CI's, come close to what we think cometary material might look like. But those meteorites weren't associated with any known meteor showers, and are likely just fragments of D-class asteroids, which may or may not be remnants of burned-out comets (comets that got trapped in the inner solar system and stripped of most of their volatiles). But, based on the above paper, even the CI's are probably not actual cometary material, though they fit the bill better than most other meteorites, for sure. Suggesting that an iron meteorite like Mazapil might be associated with a comet is nigh on preposterous - comets aren't made of iron, and shouldn't have anything to do with such a meteorite. Comets are undifferentiated bodies that have generally remained icy since their formation over four and a half billion years ago. A two or three billion year old iron with a thompson structure that took the better part of a billion years to form simply could not be from a comet. http://adsabs.harvard.edu/abs/2002M%26PS...37..649B Some more basic reading: http://www.amsmeteors.org/faqm.html#11 Scroll to section before bottom: Meteorites from Comets? http://www.pibburns.com/catastro/meteors.htm Best, Jason On Wed, Aug 11, 2010 at 9:34 PM, Meteorites USAe...@meteoritesusa.com wrote: Thanks for posting this Chris... This sounds like a good topic for an article for my magazine. If you're interested in it, and/or would like to write for the mag on this topic let me know. Anyone have a working theory based on evidence of this associative phenomena? I've heard many people suggest that meteor showers don't drop meteorites. Then I've heard people associate meteorite falls that happen during meteor showers with said shower. And I've also heard that people believe that there is ZERO connection and it's purely coincidence. So which is it? yay or nay, or maybe? or no one really knows...? Eric On 8/11/2010 8:59 PM, Chris Spratt wrote: I know of one meteor shower (November Andromedids) where an iron meteorite fell in Mazapil, Mexico during the shower. Are there any similar events? Chris Spratt Victoria, BC (Via my iPhone) __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
