Re: [meteorite-list] How much survives entry?
I think that you can usually figure that 95-99% of the mass of parent meteoroid is lost. That seems pretty consistent with the estimated mass of observed fireballs compared with the mass of recovered meteorites. Obviously, what is typical is pretty loosely defined; I don't doubt that there are exceptions to the rule. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: "Richard Kowalski" To: "meteorite list" Sent: Thursday, December 03, 2009 5:45 PM Subject: [meteorite-list] How much survives entry? Does anyone have a rough estimate on how much material, say ordinary chondrite, is lost during entry? 80% converted to light, heat and dust? 90%? 99.9%? __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
Hi list, How is this calculated and how do we know the 90% to 95% loss calculation is accurate without knowing the mass of the asteroid before entry and after recovery of every piece that lands on the surface of our planet? Has there ever been such a case? Regards, Eric Wichman Meteorites USA Chris Peterson wrote: I think that you can usually figure that 95-99% of the mass of parent meteoroid is lost. That seems pretty consistent with the estimated mass of observed fireballs compared with the mass of recovered meteorites. Obviously, what is typical is pretty loosely defined; I don't doubt that there are exceptions to the rule. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: "Richard Kowalski" To: "meteorite list" Sent: Thursday, December 03, 2009 5:45 PM Subject: [meteorite-list] How much survives entry? Does anyone have a rough estimate on how much material, say ordinary chondrite, is lost during entry? 80% converted to light, heat and dust? 90%? 99.9%? __ 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] How much survives entry?
There are recoveries following instrumentally recorded fireballs. Initial mass is estimated in different ways, depending on the data available. This includes seismic and infrasound data as well as intensity profiles, either from cameras or spacecraft. There are several papers which rigorously describe the ablation process on theoretical grounds, and these are also consistent with a 95%+ mass loss. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: "Meteorites USA" To: "Chris Peterson" Cc: "meteorite list" Sent: Thursday, December 03, 2009 9:21 PM Subject: Re: [meteorite-list] How much survives entry? Hi list, How is this calculated and how do we know the 90% to 95% loss calculation is accurate without knowing the mass of the asteroid before entry and after recovery of every piece that lands on the surface of our planet? Has there ever been such a case? __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
There's a semantic tweak to whatever answer is given. We presume on good evidence that many meteoroids result in no meteorite at all reaching the Earth. That is our assumption, at any rate. In that case, the loss is... 100% So, when we ask "how much of an ordinary chondrite is lost," are we restricting the average loss figure to only those meteoroids that produce (or seem likely to have produced) a meteorite? Do we leave out the class of 100%-loss meteoroids? A bit awkward, as they may well outnumber the meteorite-producing objects. I would say they do. The best answers are estimates. (An estimate is a computer model without any mathematics.) Richard Norton said 90% was a minimum figure for ablative loss. Chris just posted an estimate of 95% to 99% ablative loss for meteorite-producing meteoroids. We tend, sometimes unconsciously, to speak only of the meteorite-producing meteoroids. I would say that any loss less than 100% is remarkable (and good fortune). 2008TC3 at 2 to 5 meters diameter must have weighed between 10 and 150 metric tons. The four kilos recovered would suggest a minimum loss of 99.96%. Of course, there could just as easily been 40 kilos of which only 10% was recovered (99.6% loss). Or 400 kilos of which only 1% was recovered (96% loss). I think it unlikely there was 400 kilos reaching the ground, but quite possible there were 40 kilos. (Most likely fall weight would be 15 to 25 kilos.) I don't think all of it was recovered. Strewn fields a century old still yield up meteorites today. These loss estimates are based on that lowest weight estimate of ten tons... At an original 100 metric tons, the losses would be an order of magnitude higher. Now that we've proved that meteorites are impossible, well, ALMOST impossible, we can say that to produce one must require something odd about the original meteoroid --- low entry velocity, shallow entry angle, an unusually aerodynamic shape, or some combination of infrequent factors. 2008TC3 had two of those characteristics. Entry velocity was only 1600 m/s over the Earth's escape velocity and the entry angle was only 19 degrees above the local horizon. It beat the odds and reached the ground, but it paid at least a 99.9% tax to do it! Sterling K. Webb -- - Original Message - From: "Richard Kowalski" To: "meteorite list" Sent: Thursday, December 03, 2009 6:45 PM Subject: [meteorite-list] How much survives entry? Does anyone have a rough estimate on how much material, say ordinary chondrite, is lost during entry? 80% converted to light, heat and dust? 90%? 99.9%? Thanks -- Richard Kowalski http://fullmoonphotography.net IMCA #1081 __ 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] How much survives entry?
Whether a semantic tweak is required depends on how you look at the question. If you are asking how much of a meteorite's parent body was lost, there's no problem; it's never 100%. It is only in asking how much of a meteoroid survives ablation that you have to deal with the fact that it's usually 0%. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: "Sterling K. Webb" To: "Richard Kowalski" ; "meteorite list" Sent: Thursday, December 03, 2009 10:08 PM Subject: Re: [meteorite-list] How much survives entry? There's a semantic tweak to whatever answer is given. We presume on good evidence that many meteoroids result in no meteorite at all reaching the Earth. That is our assumption, at any rate. In that case, the loss is... 100% __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
> 2008TC3 at 2 to 5 meters diameter must have > weighed between 10 and 150 metric tons. The > four kilos recovered would suggest a minimum > loss of 99.96%. Of course, there could just as > easily been 40 kilos of which only 10% was > recovered (99.6% loss). Or 400 kilos of which > only 1% was recovered (96% loss). > > I think it unlikely there was 400 kilos reaching > the ground, but quite possible there were 40 kilos. > (Most likely fall weight would be 15 to 25 kilos.) > I don't think all of it was recovered. Strewn fields a > century old still yield up meteorites today. These > loss estimates are based on that lowest weight > estimate of ten tons... At an original 100 metric > tons, the losses would be an order of magnitude > higher. Regarding 2008TC3, I would like to point at a new and, in my opinion, excellent 4-page-update-summary issued by the NATURE magazine: "The impact and recovery of asteroid 2008TC3" P. Jenniskens et al., NATURE, Vol 458/26 March 2009 You have to pay a fee for an online-copy of the paper when you enter the NATURE website, but may be Professor Jenniskens or Professor Shaddad from Khartoum would be willing to share sort of a preprint or reprint - don´t know. Sorry, I have no email addresses at hands... Alex Berlin/Germany __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
I didn't say semantic tweaks don't matter... I only said that their need depends on how the question is phrased. The examples you give describe variations in physical conditions, not semantics. As I also noted in my original post, there has to be a very wide variation in reality, making it difficult to define "typical". I don't believe I used the value "99.9%" in my responses. What I said is that you can probably safely assume that in the majority of cases more than 95% of the original mass is lost. Carancas is a poor example for just about anything, being a singular event. However, even that case doesn't seem unreasonable. If we assume the impactor was 1 ton (about 1 meter diameter), a 95% loss means the parent was 20 tons (about 2 meter diameter); if we assume a 99% loss, the parent was 100 tons (about 4 meter diameter). These numbers are perfectly reasonable and believable. Of course, Carancas almost certainly had less than the usual amount of ablation because it impacted before ablation had stopped. Yes, estimates are a kind of guess. But "guess" doesn't have to mean a random choice. The idea that the parent bodies of most meteorites lost more than 95% of their mass to ablation is based on solid theory and observation. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: To: "Chris Peterson" ; "meteoritelist" Sent: Friday, December 04, 2009 12:02 PM Subject: Re: [meteorite-list] How much survives entry? Chris, Again, With all due respect. How can you say semantic tweaks don't matter? Semantics are everything. I know he asked about chondrites but they do vary in density. What if it is Iron vs, very low density like a CI1? What if it is huge vs. tiny? What if it is traveling at a super fast speed at a very steep angle? It seems TC3 came in at an angle that would argue that there would be very material little left. It also is a very porous and fragile material which would also lend itself to quick destruction entering our atmosphere. According to the show there was two different materials found. So, this meteoroid was made up of different materials which would contribute to break-up vs, holding itself together. Simple Examples here; as Sterling said without math. What if you put an iron meteorite into a rock tumbler. And then you put a CI1 into a similar rock tumbler. The amount of time it would require for these different rocks to end up as dust would be quite significant, wouldn't it? And given there is a very small time table for the ablation process to occur it seems obvious that the time spent in the ablation process alone would be sufficient to prove that the density of the meteoroid matters a lot. Secondly, The size of the material has a lot to do with ablation. Also based on time in ablation zone of the atmosphere. Using the same scenario, if you put say a marble size piece of meteorite along with a baseball size piece of the same meteorite. The marble size will have ablated to 100% dust far before the larger piece. Simple logic here. Please tell me how this example does not argue that it is in fact possible for a very high percentage of the material to survive. Lets say it's a mile wide iron traveling super fast at a 90 degree angle (which would get it through the ablation zone very quickly). It seems that it is very possible for most of it to survive. Based on your 99.9% guess. that would mean that Carancas would have entered our atmosphere the size of a small planet. We recovered aprox. 10 kilos and guesstimates are that most of it was lost to the crater. So, if you take whatever the guess is for the size that hit the ground and multiply it by 99.9% that means it would have been possibly miles wide. If it was I am surprised nobody saw it coming. Even with this highly studied event. The scientists are still arguing about the speed. One says it came in very fast while another says it came in very slow. Either way it seems to me the size estimate would also vary. So, isn't any estimate a mere guess at best? Thanks Carl -- Carl or Debbie Esparza __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
That paper is available for free on Google Docs here: http://tinyurl.com/yl7bvbg -- Richard Kowalski http://fullmoonphotography.net IMCA #1081 --- On Fri, 12/4/09, Alexander Seidel wrote: > From: Alexander Seidel > Subject: Re: [meteorite-list] How much survives entry? > To: "Sterling K. Webb" , > meteorite-list@meteoritecentral.com, damoc...@yahoo.com > Date: Friday, December 4, 2009, 6:10 AM > > 2008TC3 at 2 to 5 meters > diameter must have > > weighed between 10 and 150 metric tons. The > > four kilos recovered would suggest a minimum > > loss of 99.96%. Of course, there could just as > > easily been 40 kilos of which only 10% was > > recovered (99.6% loss). Or 400 kilos of which > > only 1% was recovered (96% loss). > > > > I think it unlikely there was 400 kilos reaching > > the ground, but quite possible there were 40 kilos. > > (Most likely fall weight would be 15 to 25 kilos.) > > I don't think all of it was recovered. Strewn fields > a > > century old still yield up meteorites today. These > > loss estimates are based on that lowest weight > > estimate of ten tons... At an original 100 metric > > tons, the losses would be an order of magnitude > > higher. > > > Regarding 2008TC3, I would like to point at a new and, > in my opinion, excellent 4-page-update-summary issued > by the NATURE magazine: > > "The impact and recovery of asteroid 2008TC3" > P. Jenniskens et al., NATURE, Vol 458/26 March 2009 > > You have to pay a fee for an online-copy of the paper > when you enter the NATURE website, but may be Professor > Jenniskens or Professor Shaddad from Khartoum would be > willing to share sort of a preprint or reprint - don´t > know. Sorry, I have no email addresses at hands... > > Alex > Berlin/Germany > __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
Sorry for my poorly formed query. I certainly did not mean that we'd include meteoroids that were so small that they completely burned up before becoming meteorites on the surface. I figured that was a given. My mistake. Yes and I did try to be a bit subtle in my query and ask about an ordinary chondrite instead of an Ureilite just to make the back of the envelope calculations easier. I am assuming someone somewhere has tested actual chondritic material in a hypersonic plasma tunnel to measure the exact amount of ablation and possibly someone here knew that result. That way it wouldn't be a guess but an actual measurement. Now that I've thought about it some more I know someone who may have already performed that experiment, so I'll contact him... Too me, 99.9% seems to me to be an excessive amount of loss due to ablation and disintegration, but maybe I'm wrong. Anyway, even if you use that number, with 2008 TC3 "weighing" an estimated 72,600 kilos before entry. 99.9% loss would mean there is still about 65 kilos of material on the ground in the Sudan that has not yet been recovered. -- Richard Kowalski http://fullmoonphotography.net IMCA #1081 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
A quick search of ADS, which i probably should have done in the first place, reveals only two papers on this and this one: DEPTH DEPENDENCE OF 22Ne/21Ne IN ORDINARY CHONDRITES AND ABLATION OF METEORITES V.A. Alexeev, Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 117975, Moscow, Russia (a...@icp.ac.ru) http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1003.pdf may be of interest to others. Not a direct ablation experiment, but it is interesting to see most of their calculations show anywhere from 14% to 99%+ ablation for various samples, with the majority in the 90s. -- Richard Kowalski http://fullmoonphotography.net IMCA #1081 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
Hi, All, Chris said: If you are asking how much of a meteorite's parent body was lost, there's no problem; it's never 100%. It is only in asking how much of a meteoroid survives ablation that you have to deal with the fact that it's usually 0%. That encapsulates two ways of looking at this question. One is to discuss a specific meteoroid / meteorite and try to deduce the specific results. The other way is as a general question concerning the entire CLASS of meteoroids / meteorites. I took the question in the general sense. Taxonomy, in other words. And, just as in all natural science, there is considerable variation in individuals and the conditions of re-entry. A plasma jet experiment will tell you ablation rates for various speeds on a specific or generalized material, but practically, this only provides broad boundaries to the problem. Very broad boundaries, because of the variances in speed, duration and the character of the material being ablated. If, for example 2003TC3 had entered at 45 degrees to the horizon at an encounter velocity of 27,500 m/s, I can practically guarantee you nothing would have reached the ground, whether it weighed 10 tons, 100 tons, or 1000 tons. [In case there are quibbles with this, yes, it would likely fragment at high altitude, but the fragments would be moving faster than 12,000 m/s and would never withstand ablation long enough to hit. I also did the calculation for both shallow entries and high-angle entries at this speed and the result is the same. Speed kills.] There are so many possible events that an empirical general answer can probably only be reached by the long-term continued operation of fireball tracking networks. So far, they suggest many meteoroids and far fewer meteorites. Sterling K. Webb -- - Original Message - From: "Richard Kowalski" To: "meteorite list" ; "Sterling K. Webb" Sent: Friday, December 04, 2009 2:42 PM Subject: Re: [meteorite-list] How much survives entry? Sorry for my poorly formed query. I certainly did not mean that we'd include meteoroids that were so small that they completely burned up before becoming meteorites on the surface. I figured that was a given. My mistake. Yes and I did try to be a bit subtle in my query and ask about an ordinary chondrite instead of an Ureilite just to make the back of the envelope calculations easier. I am assuming someone somewhere has tested actual chondritic material in a hypersonic plasma tunnel to measure the exact amount of ablation and possibly someone here knew that result. That way it wouldn't be a guess but an actual measurement. Now that I've thought about it some more I know someone who may have already performed that experiment, so I'll contact him... Too me, 99.9% seems to me to be an excessive amount of loss due to ablation and disintegration, but maybe I'm wrong. Anyway, even if you use that number, with 2008 TC3 "weighing" an estimated 72,600 kilos before entry. 99.9% loss would mean there is still about 65 kilos of material on the ground in the Sudan that has not yet been recovered. -- Richard Kowalski http://fullmoonphotography.net IMCA #1081 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
Chris, Again, With all due respect. How can you say semantic tweaks don't matter? Semantics are everything. I know he asked about chondrites but they do vary in density. What if it is Iron vs, very low density like a CI1? What if it is huge vs. tiny? What if it is traveling at a super fast speed at a very steep angle? It seems TC3 came in at an angle that would argue that there would be very material little left. It also is a very porous and fragile material which would also lend itself to quick destruction entering our atmosphere. According to the show there was two different materials found. So, this meteoroid was made up of different materials which would contribute to break-up vs, holding itself together. Simple Examples here; as Sterling said without math. What if you put an iron meteorite into a rock tumbler. And then you put a CI1 into a similar rock tumbler. The amount of time it would require for these different rocks to end up as dust would be quite significant, wouldn't it? And given there is a very small time table for the ablation process to occur it seems obvious that the time spent in the ablation process alone would be sufficient to prove that the density of the meteoroid matters a lot. Secondly, The size of the material has a lot to do with ablation. Also based on time in ablation zone of the atmosphere. Using the same scenario, if you put say a marble size piece of meteorite along with a baseball size piece of the same meteorite. The marble size will have ablated to 100% dust far before the larger piece. Simple logic here. Please tell me how this example does not argue that it is in fact possible for a very high percentage of the material to survive. Lets say it's a mile wide iron traveling super fast at a 90 degree angle (which would get it through the ablation zone very quickly). It seems that it is very possible for most of it to survive. Based on your 99.9% guess. that would mean that Carancas would have entered our atmosphere the size of a small planet. We recovered aprox. 10 kilos and guesstimates are that most of it was lost to the crater. So, if you take whatever the guess is for the size that hit the ground and multiply it by 99.9% that means it would have been possibly miles wide. If it was I am surprised nobody saw it coming. Even with this highly studied event. The scientists are still arguing about the speed. One says it came in very fast while another says it came in very slow. Either way it seems to me the size estimate would also vary. So, isn't any estimate a mere guess at best? Thanks Carl -- Carl or Debbie Esparza Meteoritemax Chris Peterson wrote: > Whether a semantic tweak is required depends on how you look at the > question. If you are asking how much of a meteorite's parent body was lost, > there's no problem; it's never 100%. It is only in asking how much of a > meteoroid survives ablation that you have to deal with the fact that it's > usually 0%. > > Chris > > * > Chris L Peterson > Cloudbait Observatory > http://www.cloudbait.com > > > - Original Message - > From: "Sterling K. Webb" > To: "Richard Kowalski" ; "meteorite list" > > Sent: Thursday, December 03, 2009 10:08 PM > Subject: Re: [meteorite-list] How much survives entry? > > > > There's a semantic tweak to whatever answer > > is given. We presume on good evidence that > > many meteoroids result in no meteorite at all > > reaching the Earth. That is our assumption, > > at any rate. In that case, the loss is... 100% > > __ > 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] How much survives entry?
Richard, Very nice show tonight. I recorded it so I can watch again. You were very very good! You are (the) ultimate meteorite hunter. Congrats. I'm pretty sure it has been stated on this list that the amount burned up in passage through the atmosphere depends on so many different factors that any guess might be right. Anyway, Congrats again. Carl -- Carl or Debbie Esparza Meteoritemax Richard Kowalski wrote: > Does anyone have a rough estimate on how much material, say ordinary > chondrite, is lost during entry? 80% converted to light, heat and dust? 90%? > 99.9%? > > Thanks > > -- > Richard Kowalski > http://fullmoonphotography.net > IMCA #1081 > > > > __ > 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] How much survives entry?
To get a visceral sense of why so little material survives entry, we can do a simple back-of-the-envelope calculation that lets us ignore messy details like entry angle, composition, and ablation physics. A very slow meteoroid (12 km/s) entering the atmosphere is carrying a kinetic energy of 72 MJ/kg. That's the equivalent of 17 kg of TNT per kg of meteoroid. Usually, all of that energy is dissipated in at most a few seconds (for our purposes, any surviving meteorites can be considered to have zero kinetic energy). A meteoroid that enters at 26 km/s (still slow enough for meteorites) gives up 338 MJ/kg, or 80 kg TNT per kg. Not hard to see from this just how rough a ride those meteoroids experience. The energy is what it is; the primary factor that determines survival is how long the energy is allowed to dissipate. That's why long lasting fireballs are much better candidates for meteorite producers than shorter ones. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: To: "Richard Kowalski" ; "meteoritelist" Sent: Thursday, December 03, 2009 9:32 PM Subject: Re: [meteorite-list] How much survives entry? Richard, Very nice show tonight. I recorded it so I can watch again. You were very very good! You are (the) ultimate meteorite hunter. Congrats. I'm pretty sure it has been stated on this list that the amount burned up in passage through the atmosphere depends on so many different factors that any guess might be right. Anyway, Congrats again. Carl __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] How much survives entry?
mass converted to light would require fusion. all of the mass of a meteorite is retained by the earth. most is dust from ablation. how much reaches the ground depends on a lot of variables like velocity of impact angle of impact, specific gravity of meteorite, water content or volatile gas content of meteorite. even the humidity of the air or density of ion count in the magnetosphere. in most cases all of the meteorite vaporises. or explodes. from impact with the ionosphere. its very thin but like hitting a brick wall at 17kmph. so saying how much is going to survive is like asking how many licks it will take to get to the center of a tootsiepop lol --- On Thu, 12/3/09, Chris Peterson wrote: > From: Chris Peterson > Subject: Re: [meteorite-list] How much survives entry? > To: "meteorite list" > Date: Thursday, December 3, 2009, 9:39 PM > I think that you can usually figure > that 95-99% of the mass of parent meteoroid is lost. That > seems pretty consistent with the estimated mass of observed > fireballs compared with the mass of recovered meteorites. > > Obviously, what is typical is pretty loosely defined; I > don't doubt that there are exceptions to the rule. > > Chris > > * > Chris L Peterson > Cloudbait Observatory > http://www.cloudbait.com > > > - Original Message - From: "Richard Kowalski" > > To: "meteorite list" > Sent: Thursday, December 03, 2009 5:45 PM > Subject: [meteorite-list] How much survives entry? > > > > Does anyone have a rough estimate on how much > material, say ordinary chondrite, is lost during entry? 80% > converted to light, heat and dust? 90%? 99.9%? > > __ > 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] How much survives entry?
It's certainly true in the strictest sense that virtually 100% of the mass survives entry. However, I think most people here quite correctly interpreted the original question in terms of how much mass ends up as something you can hold in your hand at the end of the day- not dust and gas! Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: "Steve Dunklee" To: "meteorite list" ; "Chris Peterson" Sent: Monday, December 07, 2009 7:35 AM Subject: Re: [meteorite-list] How much survives entry? mass converted to light would require fusion. all of the mass of a meteorite is retained by the earth. most is dust from ablation. how much reaches the ground depends on a lot of variables like velocity of impact angle of impact, specific gravity of meteorite, water content or volatile gas content of meteorite. even the humidity of the air or density of ion count in the magnetosphere. in most cases all of the meteorite vaporises. or explodes. from impact with the ionosphere. its very thin but like hitting a brick wall at 17kmph. so saying how much is going to survive is like asking how many licks it will take to get to the center of a tootsiepop lol __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
