Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Steve, Is N2N3 not a purely chemical reaction? In what sense is it nuclear? Perhaps I am misinterpreting this. Regards, John On 28/02/2013 00:49, Steve Dunklee steve.dunk...@yahoo.com wrote: Ouch! Imagine the extra energy released if the detonation occured inside a thunderhead? I had a physics instructor who thought small amounts of nuclear reactions were caused by lightning as in nitrogen converted to ozone. He said keep your eyes open. Just because something is improbable it doesnt make it impossible. Some detonations happen when pressures get to high as stated by Chris Peterson but others happen when the forward pressure suddenly drops causing expasion or instability. most are the result of some kind of forward pressure change be it up or down. cheers Steve --- On Thu, 2/28/13, James Beauchamp falco...@sbcglobal.net wrote: From: James Beauchamp falco...@sbcglobal.net Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com, drtanuki drtan...@yahoo.com Date: Thursday, February 28, 2013, 4:52 AM Hi Dirk, A very small amount of equivalent energy is involved with free electron release. Perhaps the moving electrons cause localized magnetic fields, but far lower than those needed to have large-scale charge separation. I can see the electron clouds on the radar because free electrons are conductive. But energy exchange is kept pretty locally. Now, posing in intriguing situation - lets say a russian-like event occurs over a supercell thunderstorm. It could skim across the anvil. The line of conducting plasma would short circuit the heavily charge separated areas (Charges migrate due to the supercooled freezing process). I think you would get a nice lightshow. Kind of interesting... CC meteortites, low pressure. Volatile amino acids, carbon, and lightning, Would be a nice situation for early life forms. --- On Wed, 2/27/13, drtanuki drtan...@yahoo.com wrote: From: drtanuki drtan...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com Date: Wednesday, February 27, 2013, 2:15 AM Garry and Steve, Most excellent posts and information; thank you. Further to my original question. Would/should we expect that there may be ground-to-air electro-stactic response (lightning) prior to the arrival of the physical body to physical contact with the earth; and has this been simulated or captured on video? Dirk Ross...Tokyo --- On Wed, 2/27/13, Garry Stewart xe...@yahoo.com wrote: From: Garry Stewart xe...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: drtanuki drtan...@yahoo.com Date: Wednesday, February 27, 2013, 4:33 PM Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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 __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
In plasma situations where electrons and nuclei are freely moving about, the math supports a very, very tiny chance that nuclei will collide with enough energy to merge or break apart into other isotopes. Applying a rate of trillions of possibilities in a volume, over a period of time, the probability becomes realizable that somewhere, something happened. There's a whole sub-culture of people who build fuzors in their garages for the novelty of saying there's a chance something is fusing in that glowing cloud. --- On Thu, 2/28/13, Pict p...@pict.co.uk wrote: From: Pict p...@pict.co.uk Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Meteorite-list@meteoritecentral.com Date: Thursday, February 28, 2013, 1:59 AM Steve, Is N2N3 not a purely chemical reaction? In what sense is it nuclear? Perhaps I am misinterpreting this. Regards, John On 28/02/2013 00:49, Steve Dunklee steve.dunk...@yahoo.com wrote: Ouch! Imagine the extra energy released if the detonation occured inside a thunderhead? I had a physics instructor who thought small amounts of nuclear reactions were caused by lightning as in nitrogen converted to ozone. He said keep your eyes open. Just because something is improbable it doesnt make it impossible. Some detonations happen when pressures get to high as stated by Chris Peterson but others happen when the forward pressure suddenly drops causing expasion or instability. most are the result of some kind of forward pressure change be it up or down. cheers Steve --- On Thu, 2/28/13, James Beauchamp falco...@sbcglobal.net wrote: From: James Beauchamp falco...@sbcglobal.net Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com, drtanuki drtan...@yahoo.com Date: Thursday, February 28, 2013, 4:52 AM Hi Dirk, A very small amount of equivalent energy is involved with free electron release. Perhaps the moving electrons cause localized magnetic fields, but far lower than those needed to have large-scale charge separation. I can see the electron clouds on the radar because free electrons are conductive. But energy exchange is kept pretty locally. Now, posing in intriguing situation - lets say a russian-like event occurs over a supercell thunderstorm. It could skim across the anvil. The line of conducting plasma would short circuit the heavily charge separated areas (Charges migrate due to the supercooled freezing process). I think you would get a nice lightshow. Kind of interesting... CC meteortites, low pressure. Volatile amino acids, carbon, and lightning, Would be a nice situation for early life forms. --- On Wed, 2/27/13, drtanuki drtan...@yahoo.com wrote: From: drtanuki drtan...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com Date: Wednesday, February 27, 2013, 2:15 AM Garry and Steve, Most excellent posts and information; thank you. Further to my original question. Would/should we expect that there may be ground-to-air electro-stactic response (lightning) prior to the arrival of the physical body to physical contact with the earth; and has this been simulated or captured on video? Dirk Ross...Tokyo --- On Wed, 2/27/13, Garry Stewart xe...@yahoo.com wrote: From: Garry Stewart xe...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: drtanuki drtan...@yahoo.com Date: Wednesday, February 27, 2013, 4:33 PM Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ Visit
Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Garry and Steve, Most excellent posts and information; thank you. Further to my original question. Would/should we expect that there may be ground-to-air electro-stactic response (lightning) prior to the arrival of the physical body to physical contact with the earth; and has this been simulated or captured on video? Dirk Ross...Tokyo --- On Wed, 2/27/13, Garry Stewart xe...@yahoo.com wrote: From: Garry Stewart xe...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: drtanuki drtan...@yahoo.com Date: Wednesday, February 27, 2013, 4:33 PM Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Dirk and List, Somebody with three letters after their name caused this explanation: As a high velocity meteoroid encounters denser atmosphere, there exists an increasing pressure difference between its frontal and rearward areas. This plus the very high temperatures create the instabilities that ultimately cause the sudden destruction of the body. Chrondite meteoroids are more vulnerable to this type of destruction than iron/nickel bodies because of lesser strength. Now, I as a layman think that what causes a perceived explosion is as above, but more succintly, that the the compression wave created at the leading area of the mass collides with the stationary refractory wave that is almost instantaneously being generated at the rear of the mass. Sort of like clapping your hands together while moving your arms rapidly in one direction. Regards, Guido -Original Message- From: drtanuki drtan...@yahoo.com Sent: Feb 26, 2013 10:59 PM To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
A body larger than about a centimeter transfers its kinetic energy to other forms primarily by compressing the air in front of it as it descends into the atmosphere. The pressure involved is typically very large- tens or hundreds of megapascals for meter-class bodies. Once this ram pressure exceeds the material strength of the body, it breaks apart (presumably along existing fault lines, so the material properties of the body are important- and generally unknown). Before the breakup, the heat created by compressing air is melting the surface of the meteoroid, resulting in ablation. This ablation is responsible for some of the light we see (along with atmospheric ionization from the same heat source), but is not particularly disruptive to the meteoroid. Only the outer surface is affected. Ablation is a very efficient way of removing energy (which is why spacecraft heat shields prior to the shuttles were ablative). When the meteoroid fragments at hypersonic speeds, however, additional surface area is instantly exposed, resulting in a rapid heating of the surrounding air (which is just a fancy way of saying explosion). If a body breaks into just a few pieces, as is common, we may see a central or terminal brightening. If it completely shatters into thousands of pieces (as seems likely with Chelyabinsk) the energy from the suddenly heated air is immense- an efficient conversion of kinetic energy to thermal energy. The expanding hot air can produce an impressive sonic wave, and probably further disrupts the meteoroid itself. I don't that there are any electrical forces of a significant size to affect the structure or motion of the meteoroid, although atmospheric electrical effects probably occur (e.g. electrophonics). Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/26/2013 11:59 PM, drtanuki wrote: Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Chris, Do you have any references you could point me to for how break-up scales with size-mass-physical properties etc. of meteoroids. I am interested in knowing the sweet-spot for yielding meteorites on the ground. In other words, when is a meteoroid too small or too big to produce significant large pieces of surviving material? It seems like Chelyabinsk is outside the sweet spot as it apparently produced mostly fragments even though it had large mass. On the other hand much bigger masses may also survive. Is it bimodal? Thanks, Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://meteorite.unm.edu/people/carl_agee/ On Wed, Feb 27, 2013 at 9:21 AM, Chris Peterson c...@alumni.caltech.edu wrote: A body larger than about a centimeter transfers its kinetic energy to other forms primarily by compressing the air in front of it as it descends into the atmosphere. The pressure involved is typically very large- tens or hundreds of megapascals for meter-class bodies. Once this ram pressure exceeds the material strength of the body, it breaks apart (presumably along existing fault lines, so the material properties of the body are important- and generally unknown). Before the breakup, the heat created by compressing air is melting the surface of the meteoroid, resulting in ablation. This ablation is responsible for some of the light we see (along with atmospheric ionization from the same heat source), but is not particularly disruptive to the meteoroid. Only the outer surface is affected. Ablation is a very efficient way of removing energy (which is why spacecraft heat shields prior to the shuttles were ablative). When the meteoroid fragments at hypersonic speeds, however, additional surface area is instantly exposed, resulting in a rapid heating of the surrounding air (which is just a fancy way of saying explosion). If a body breaks into just a few pieces, as is common, we may see a central or terminal brightening. If it completely shatters into thousands of pieces (as seems likely with Chelyabinsk) the energy from the suddenly heated air is immense- an efficient conversion of kinetic energy to thermal energy. The expanding hot air can produce an impressive sonic wave, and probably further disrupts the meteoroid itself. I don't that there are any electrical forces of a significant size to affect the structure or motion of the meteoroid, although atmospheric electrical effects probably occur (e.g. electrophonics). Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/26/2013 11:59 PM, drtanuki wrote: Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Chris and all, I will refine my questions a bit regarding the Russian asteroid (meteoroid) body: Could resonance (differential-harmonics) within the body cause disintegration? Can we expect to see an Earth-ground electrical discharge towards the meteoroid? Is it possible? And could differential electrical charges on the leading and trailing part of the body cause internal disruption leading to disintegration? Thank you. Forgive me if my questions are poorly based or asked. Dirk Ross...Tokyo --- On Thu, 2/28/13, Chris Peterson c...@alumni.caltech.edu wrote: From: Chris Peterson c...@alumni.caltech.edu Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: meteorite-list@meteoritecentral.com Date: Thursday, February 28, 2013, 1:21 AM A body larger than about a centimeter transfers its kinetic energy to other forms primarily by compressing the air in front of it as it descends into the atmosphere. The pressure involved is typically very large- tens or hundreds of megapascals for meter-class bodies. Once this ram pressure exceeds the material strength of the body, it breaks apart (presumably along existing fault lines, so the material properties of the body are important- and generally unknown). Before the breakup, the heat created by compressing air is melting the surface of the meteoroid, resulting in ablation. This ablation is responsible for some of the light we see (along with atmospheric ionization from the same heat source), but is not particularly disruptive to the meteoroid. Only the outer surface is affected. Ablation is a very efficient way of removing energy (which is why spacecraft heat shields prior to the shuttles were ablative). When the meteoroid fragments at hypersonic speeds, however, additional surface area is instantly exposed, resulting in a rapid heating of the surrounding air (which is just a fancy way of saying explosion). If a body breaks into just a few pieces, as is common, we may see a central or terminal brightening. If it completely shatters into thousands of pieces (as seems likely with Chelyabinsk) the energy from the suddenly heated air is immense- an efficient conversion of kinetic energy to thermal energy. The expanding hot air can produce an impressive sonic wave, and probably further disrupts the meteoroid itself. I don't that there are any electrical forces of a significant size to affect the structure or motion of the meteoroid, although atmospheric electrical effects probably occur (e.g. electrophonics). Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/26/2013 11:59 PM, drtanuki wrote: Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Chris, Working on oil and gas wells it is routine to test the fracture point of the rock at the bottom of the well after having run and cemented a casing string (leak off test). You do this by shutting in the well at surface and pumping incremental volumes of mud into the hole and noting the rise in surface pressure with each injection. When the rock is behaving elastically the rise in pressure is linear with volume, but you can see when the rock has reached its elastic limit when the pressure increase with volume becomes less. This occurs at the onset of fracture generation, and continued pumping typically results in extensive fracture propagation and an actual lowering of surface pressure as it is dissipated by mud flowing into the fractures. Same principal is employed with hydraulic fracturing to increase production surface from low permeability lithologies (shale etc). Empirically testing the fracture point of the rock gives you a handle on the maximum mud density the well can sustain when drilling the next hole section, and the maximum pressure one could hold at surface with the BOP in the event of encountering formation pressure in excess of the mud hydrostatic. If you exceed the fracture pressure by increasing the mud 'weight' (density) to control formation pressure, the danger is you induce fractures, lose height in your your mud column as it drains into the wellbore thereby reducing hydrostatic pressure at the bottom of the well and thereby risking falling below the formation pressure inducing the well to flow (kick) or blowout in the worst case. Shutting a flowing well in with the BOP when the formation pressure is higher than the mud hydrostatic (I.e. Flowing) you ideally do not want the surface pressure plus the mud hydrostatic to exceed the 'leak off' as then you run the risk of an underground blowout where the high formation pressure flowing zone breaks down a weaker zone (generally higher up) and flows formation fluid (oil/water/gas) into it displacing the mud present between the two zones. I apologise for the off topic background above but I am wondering if the disintegration mechanism is analogous for a meteor. The pressures you quote at the leading surface of the meteor are in the typical range I would expect from the well experience. Presumably the pressure at the rear is relatively low, and the pressure cannot dissipate around the object due to the speed of entry exceeding the speed of flow of compressed air around it. So if this pressure differential is applied to the front of the object there must come a point where the elastic limit is breached, fractures are induced, and then rapidly propagate. Once there are multiple paths of pressure communication through the former solid object rather than around it, there is presumably a rapid lowering of differential pressure from front to rear occurring as air rushes through the gaps between the fractured pieces and expands as the pressure lowers towards the rear of the disintegrating meteor pushing everything apart (I.e. Exploding). As Chris says this also vastly increases the surface area for incandescence and the the luminosity might be expected to greatly increase. I am wondering if this is at all a realistic description of what might be going on? I am unsure of the temperatures involved at the leading edge and in any case I can't find phase properties for water at those extremes, but also wonder if water exists as a liquid or gaseous phase at the leading edge or is it entirely plasma?. I'm sure the pressure would take it past the dewpoint but is the elevated temperature sufficient to prevent condensation at some point so that a liquid 'injection' phase forms at some point during disintegration and collapse of the initial pressure differential? Condensed water seems evident in the trail judging by white colour evident in some 'smoke trails'. Are there any published properties for typical chondrites/irons/mesosiderites available (e.g. Porosity, permeability, Poisson's ratio etc), and have any destructive pressure experiments been conducted to determine failure mechanisms for these materials? I presume the ductility inherent in irons versus the brittle nature of chondrites results in disintegration along far fewer planes of fracture, generally resulting in larger pieces after failure. Regards, John On 27/02/2013 09:21, Chris Peterson c...@alumni.caltech.edu wrote: A body larger than about a centimeter transfers its kinetic energy to other forms primarily by compressing the air in front of it as it descends into the atmosphere. The pressure involved is typically very large- tens or hundreds of megapascals for meter-class bodies. Once this ram pressure exceeds the material strength of the body, it breaks apart (presumably along existing fault lines, so the material properties of the body are important- and generally unknown). Before the breakup, the heat created by compressing air is melting the surface of the meteoroid, resulting
Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi John- I don't doubt that there are analogs between the fracturing you describe at the bottom of a well and what happens with a meteor. However, there may be some fundamental material differences. The rock at the bottom of the well is typically very large compared with the area where pressure is applied, and is already under high pressure. A meteoroid may range from nearly monolithic (particularly in the case of an iron body) to something like a rubble pile. Obviously, the response to a non-isotropic force from ram pressure will be very different in those cases. I'm not sure what happens to water during meteoritic flight. Most meteor trails are largely composed of dust, but if water trails are observed, I suspect they are largely produced in the same way that many airplane contrails are- the condensation of existing atmospheric water vapor onto solid particles, particularly in response to aerodynamic effects such as vortex production. There is lots of published information on the material properties of meteoritic material, but that is only of limited value in explaining the behavior of meteors, since the microscopic bulk properties are largely unrelated to the material properties extended over a meter-class or larger body. This is why we don't usually know much about the class of material producing a large fireball until an actual recovery is made. The fireball observations alone simply aren't enough. In fact, the best information on possible material comes not from how the meteor breaks up, but from the deceleration profile and mass estimates. Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/27/2013 11:52 AM, Pict wrote: Chris, Working on oil and gas wells it is routine to test the fracture point of the rock at the bottom of the well after having run and cemented a casing string (leak off test). You do this by shutting in the well at surface and pumping incremental volumes of mud into the hole and noting the rise in surface pressure with each injection. When the rock is behaving elastically the rise in pressure is linear with volume, but you can see when the rock has reached its elastic limit when the pressure increase with volume becomes less. This occurs at the onset of fracture generation, and continued pumping typically results in extensive fracture propagation and an actual lowering of surface pressure as it is dissipated by mud flowing into the fractures. Same principal is employed with hydraulic fracturing to increase production surface from low permeability lithologies (shale etc). Empirically testing the fracture point of the rock gives you a handle on the maximum mud density the well can sustain when drilling the next hole section, and the maximum pressure one could hold at surface with the BOP in the event of encountering formation pressure in excess of the mud hydrostatic. If you exceed the fracture pressure by increasing the mud 'weight' (density) to control formation pressure, the danger is you induce fractures, lose height in your your mud column as it drains into the wellbore thereby reducing hydrostatic pressure at the bottom of the well and thereby risking falling below the formation pressure inducing the well to flow (kick) or blowout in the worst case. Shutting a flowing well in with the BOP when the formation pressure is higher than the mud hydrostatic (I.e. Flowing) you ideally do not want the surface pressure plus the mud hydrostatic to exceed the 'leak off' as then you run the risk of an underground blowout where the high formation pressure flowing zone breaks down a weaker zone (generally higher up) and flows formation fluid (oil/water/gas) into it displacing the mud present between the two zones. I apologise for the off topic background above but I am wondering if the disintegration mechanism is analogous for a meteor. The pressures you quote at the leading surface of the meteor are in the typical range I would expect from the well experience. Presumably the pressure at the rear is relatively low, and the pressure cannot dissipate around the object due to the speed of entry exceeding the speed of flow of compressed air around it. So if this pressure differential is applied to the front of the object there must come a point where the elastic limit is breached, fractures are induced, and then rapidly propagate. Once there are multiple paths of pressure communication through the former solid object rather than around it, there is presumably a rapid lowering of differential pressure from front to rear occurring as air rushes through the gaps between the fractured pieces and expands as the pressure lowers towards the rear of the disintegrating meteor pushing everything apart (I.e. Exploding). As Chris says this also vastly increases the surface area for incandescence and the the luminosity might be expected to greatly increase. I am wondering if this is at all a realistic description of what
Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Carl- For the most part, breakup characteristics don't correlate well with either size or material. I think it's largely a matter of the bulk properties of the meteoroid- how monolithic versus faulted it is- and any material can exist on a wide range between those extremes. For the most part, I'd say if there's any sweet-spot, it is largely determined by the same factors that have been seen as key for a long time- a shallow entry angle, low entry speed, and low altitude terminal explosion all bode well for meteorite production. Of course, larger bodies have more material, and might well be expected to yield more meteorites under equivalent entry conditions. But that's a very broad generalization. I think that the nature of the terminal explosion of Chelyabinsk resulted in such tiny fragmentation that something in excess of 99% of the initial mass was lost. A somewhat stronger body of the same size might have survived a little longer, slowing enough that the disruption would be less violent, and a lot more could survive. Consider that Sikhote-Alin was a smaller body, but much more material survived to the ground- both because it was materially stronger, and because it didn't explode until it was much lower. Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/27/2013 10:42 AM, Carl Agee wrote: Hi Chris, Do you have any references you could point me to for how break-up scales with size-mass-physical properties etc. of meteoroids. I am interested in knowing the sweet-spot for yielding meteorites on the ground. In other words, when is a meteoroid too small or too big to produce significant large pieces of surviving material? It seems like Chelyabinsk is outside the sweet spot as it apparently produced mostly fragments even though it had large mass. On the other hand much bigger masses may also survive. Is it bimodal? Thanks, Carl Agee __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Chris, there are indeed obvious differences. However, typically in leak-off tests you are applying pressure to a relatively small area, maybe inside a cylinder 6ft long and 1ft in diameter (you might typically drill 2m of new formation below the casing shoe prior to the test). The rock is however prestressed by the overburden load and formation pore pressure so that needs to be overcome to an extent before 'expansional' stress is applied to the matrix itself. Once the 'preloading' is overcome however, I think perhaps it is an analogous situation - a small volume of rock with a significant stress gradient across it. I really was wondering what happens to the pressure distribution around the meteor when a multitude of fractures rapidly propagate through a monolithic body offering additional pathways for pressure equalisation front to rear, and if the resulting redistribution of pressure through these fracture pathways could be a mechanism to change a solid body into a dispersed cloud of rubble (i.e. Blow it up) rather than a fragmented rock continuing in tight formation. I'm sure it's a complicated scenario to model. Alternatively, the vastly increased surface area from the near instantaneous formation of a multitude of pieces might be the cause because of a sharp rise in drag drastically augmenting thermal dissipation of kinetic energy. Seems an equally plausible explanation within the confines of my imagination. Regards, John On 27/02/2013 12:58, Chris Peterson c...@alumni.caltech.edu wrote: Hi John- I don't doubt that there are analogs between the fracturing you describe at the bottom of a well and what happens with a meteor. However, there may be some fundamental material differences. The rock at the bottom of the well is typically very large compared with the area where pressure is applied, and is already under high pressure. A meteoroid may range from nearly monolithic (particularly in the case of an iron body) to something like a rubble pile. Obviously, the response to a non-isotropic force from ram pressure will be very different in those cases. I'm not sure what happens to water during meteoritic flight. Most meteor trails are largely composed of dust, but if water trails are observed, I suspect they are largely produced in the same way that many airplane contrails are- the condensation of existing atmospheric water vapor onto solid particles, particularly in response to aerodynamic effects such as vortex production. There is lots of published information on the material properties of meteoritic material, but that is only of limited value in explaining the behavior of meteors, since the microscopic bulk properties are largely unrelated to the material properties extended over a meter-class or larger body. This is why we don't usually know much about the class of material producing a large fireball until an actual recovery is made. The fireball observations alone simply aren't enough. In fact, the best information on possible material comes not from how the meteor breaks up, but from the deceleration profile and mass estimates. Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/27/2013 11:52 AM, Pict wrote: Chris, Working on oil and gas wells it is routine to test the fracture point of the rock at the bottom of the well after having run and cemented a casing string (leak off test). You do this by shutting in the well at surface and pumping incremental volumes of mud into the hole and noting the rise in surface pressure with each injection. When the rock is behaving elastically the rise in pressure is linear with volume, but you can see when the rock has reached its elastic limit when the pressure increase with volume becomes less. This occurs at the onset of fracture generation, and continued pumping typically results in extensive fracture propagation and an actual lowering of surface pressure as it is dissipated by mud flowing into the fractures. Same principal is employed with hydraulic fracturing to increase production surface from low permeability lithologies (shale etc). Empirically testing the fracture point of the rock gives you a handle on the maximum mud density the well can sustain when drilling the next hole section, and the maximum pressure one could hold at surface with the BOP in the event of encountering formation pressure in excess of the mud hydrostatic. If you exceed the fracture pressure by increasing the mud 'weight' (density) to control formation pressure, the danger is you induce fractures, lose height in your your mud column as it drains into the wellbore thereby reducing hydrostatic pressure at the bottom of the well and thereby risking falling below the formation pressure inducing the well to flow (kick) or blowout in the worst case. Shutting a flowing well in with the BOP when the formation pressure is higher than the mud hydrostatic (I.e. Flowing) you ideally do not want the
Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Dirk and all! There were so many different pressures placed on this object, not sure you could point to a single one conclusively to answer your question about resonance. You would have to define the causes to consider resonance. I suppose if we knew the air density we could SWAG the ram pressure (which I'd guess may be the single largest contributor) as the mass has already been determined. I have not heard anyone give those details yet. Was the mass determined upon entry or when it burst? It did have some time to ablate. I think the physicists have their work cut out and I look forward to reading about it! In regards to the strewn field. I think it's going to take a lot of time to determine it. They have a great opportunity to record a spectacular strewn field. The frenzy probably hosed that hope up already. With other known strewn fields, such as JaH 073 at ~19.6km long and Franconia at ~17km long, it may take a while to find large fragments. We know in both of these fields, thousands of small 0-20 gram fragments were recovered on the beginning end and middle of the fields and much much larger fragments down field many kilometers away. I am hoping to hear some 40kg + frags are found! Cheers! Jim Wooddell On Wed, Feb 27, 2013 at 11:36 AM, drtanuki drtan...@yahoo.com wrote: Chris and all, I will refine my questions a bit regarding the Russian asteroid (meteoroid) body: Could resonance (differential-harmonics) within the body cause disintegration? Can we expect to see an Earth-ground electrical discharge towards the meteoroid? Is it possible? And could differential electrical charges on the leading and trailing part of the body cause internal disruption leading to disintegration? Thank you. Forgive me if my questions are poorly based or asked. Dirk Ross...Tokyo --- On Thu, 2/28/13, Chris Peterson c...@alumni.caltech.edu wrote: From: Chris Peterson c...@alumni.caltech.edu Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: meteorite-list@meteoritecentral.com Date: Thursday, February 28, 2013, 1:21 AM A body larger than about a centimeter transfers its kinetic energy to other forms primarily by compressing the air in front of it as it descends into the atmosphere. The pressure involved is typically very large- tens or hundreds of megapascals for meter-class bodies. Once this ram pressure exceeds the material strength of the body, it breaks apart (presumably along existing fault lines, so the material properties of the body are important- and generally unknown). Before the breakup, the heat created by compressing air is melting the surface of the meteoroid, resulting in ablation. This ablation is responsible for some of the light we see (along with atmospheric ionization from the same heat source), but is not particularly disruptive to the meteoroid. Only the outer surface is affected. Ablation is a very efficient way of removing energy (which is why spacecraft heat shields prior to the shuttles were ablative). When the meteoroid fragments at hypersonic speeds, however, additional surface area is instantly exposed, resulting in a rapid heating of the surrounding air (which is just a fancy way of saying explosion). If a body breaks into just a few pieces, as is common, we may see a central or terminal brightening. If it completely shatters into thousands of pieces (as seems likely with Chelyabinsk) the energy from the suddenly heated air is immense- an efficient conversion of kinetic energy to thermal energy. The expanding hot air can produce an impressive sonic wave, and probably further disrupts the meteoroid itself. I don't that there are any electrical forces of a significant size to affect the structure or motion of the meteoroid, although atmospheric electrical effects probably occur (e.g. electrophonics). Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 2/26/2013 11:59 PM, drtanuki wrote: Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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 -- Jim Wooddell jimwoodd...@gmail.com 928-247-2675 __ Visit
Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Hi Dirk, A very small amount of equivalent energy is involved with free electron release. Perhaps the moving electrons cause localized magnetic fields, but far lower than those needed to have large-scale charge separation. I can see the electron clouds on the radar because free electrons are conductive. But energy exchange is kept pretty locally. Now, posing in intriguing situation - lets say a russian-like event occurs over a supercell thunderstorm. It could skim across the anvil. The line of conducting plasma would short circuit the heavily charge separated areas (Charges migrate due to the supercooled freezing process). I think you would get a nice lightshow. Kind of interesting... CC meteortites, low pressure. Volatile amino acids, carbon, and lightning, Would be a nice situation for early life forms. --- On Wed, 2/27/13, drtanuki drtan...@yahoo.com wrote: From: drtanuki drtan...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com Date: Wednesday, February 27, 2013, 2:15 AM Garry and Steve, Most excellent posts and information; thank you. Further to my original question. Would/should we expect that there may be ground-to-air electro-stactic response (lightning) prior to the arrival of the physical body to physical contact with the earth; and has this been simulated or captured on video? Dirk Ross...Tokyo --- On Wed, 2/27/13, Garry Stewart xe...@yahoo.com wrote: From: Garry Stewart xe...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: drtanuki drtan...@yahoo.com Date: Wednesday, February 27, 2013, 4:33 PM Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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 __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Ouch! Imagine the extra energy released if the detonation occured inside a thunderhead? I had a physics instructor who thought small amounts of nuclear reactions were caused by lightning as in nitrogen converted to ozone. He said keep your eyes open. Just because something is improbable it doesnt make it impossible. Some detonations happen when pressures get to high as stated by Chris Peterson but others happen when the forward pressure suddenly drops causing expasion or instability. most are the result of some kind of forward pressure change be it up or down. cheers Steve --- On Thu, 2/28/13, James Beauchamp falco...@sbcglobal.net wrote: From: James Beauchamp falco...@sbcglobal.net Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com, drtanuki drtan...@yahoo.com Date: Thursday, February 28, 2013, 4:52 AM Hi Dirk, A very small amount of equivalent energy is involved with free electron release. Perhaps the moving electrons cause localized magnetic fields, but far lower than those needed to have large-scale charge separation. I can see the electron clouds on the radar because free electrons are conductive. But energy exchange is kept pretty locally. Now, posing in intriguing situation - lets say a russian-like event occurs over a supercell thunderstorm. It could skim across the anvil. The line of conducting plasma would short circuit the heavily charge separated areas (Charges migrate due to the supercooled freezing process). I think you would get a nice lightshow. Kind of interesting... CC meteortites, low pressure. Volatile amino acids, carbon, and lightning, Would be a nice situation for early life forms. --- On Wed, 2/27/13, drtanuki drtan...@yahoo.com wrote: From: drtanuki drtan...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: Garry Stewart xe...@yahoo.com, meteorite-list@meteoritecentral.com, steve.dunk...@yahoo.com Date: Wednesday, February 27, 2013, 2:15 AM Garry and Steve, Most excellent posts and information; thank you. Further to my original question. Would/should we expect that there may be ground-to-air electro-stactic response (lightning) prior to the arrival of the physical body to physical contact with the earth; and has this been simulated or captured on video? Dirk Ross...Tokyo --- On Wed, 2/27/13, Garry Stewart xe...@yahoo.com wrote: From: Garry Stewart xe...@yahoo.com Subject: Re: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? To: drtanuki drtan...@yahoo.com Date: Wednesday, February 27, 2013, 4:33 PM Hi Dirk and List, This link http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b1.html explains the propagation of atomic shockwaves with interesting pictures of shockwave propagation. It can explain the effects on meteoric explosions at high altitude. Interesting read but very long article and detailed. - Original Message - From: drtanuki drtan...@yahoo.com To: meteorite-list@meteoritecentral.com Cc: Sent: Wednesday, February 27, 2013 12:59 AM Subject: [meteorite-list] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties? Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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 __ 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] Meteoroid/Asteroid Electro-Magnetic Disruption and Charge Properties?
Dear List, If there is anyone willing to discuss the how and why meteoroids/asteroids detonate please explain for the list and myself. I am interested learning more about the electrical/mechanical/physical forces that these bodies undergo as they reach the earth such as in the latest Russian event. Thank you. Dirk Ross...Tokyo __ 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
