[meteorite-list] Temperature of meteorites
Original Message processed by Tobit InfoCenter Subject: Re: [meteorite-list] Temperature of meteorites (24-Nov-2010 11:17) From: hr...@aon.at To: bernd.pa...@paulinet.de Hello All, Again forwarding something ... this time from Herbert Raab: Zelimir Gabelica wrote: Are there data reporting cold, frozen or alike meteorites ? In the Natural History Museum in Vienna, there is a slice of Dhurmsala on display. The label reads: Dhurmsala. Gefallen 14.Juli 1869. Kam so kalt zur Erde, dass er nicht in der Hand gehalten werden konnte. Einziger derartiger Fall. (Dhurmsala. Fell July 14, 1869. Reached [the surface of] the Earth so cold that it was not possible to hold it in the hand. Only known such case.) Haidinger, in his description of the 1866 fall of Knyahinya, writes: Der israelitische Gastwirth gab die bestimmte Äußerung ab, daß der Stein, der, wo er saß, vor ihm herabfiel, und den er sogleich aufhob, eiskalt war, aber daß ihm die Hand intensiv nach Schwefel - und Pulver, auch Knoblauch - wie der Ausdruck war - roch, so zwar, daß die Hand noch zwei Tage lang den Geruch beibehielt. (The israelitic innkeeper gave the certain statement that the stone which fell in front of him, where he sat, and that was picked up immediately, was ice-cold, but that his hand smelled like sulfur - and [gun]powder, even garlic - as his words were - and that the had kept that smell for two days.) Best greetings, Herbert __ 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] Temperature of meteorites - Correction of typo
and that the *hand had kept* that smell for two days. __ 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] Temperature of meteorites - Correction of typo
Greetings, Hands down, meteorites are cold when they land :-) Apollo Astronauts reported the smell of gun powder from the moon dust. Perhaps many bodies in the solar system have that smell. Falling through the atmosphere should remove the regolith though, except where it is cemented in from past impacts and part of the interior of an meteoroid. --AL Mitterling Quoting bernd.pa...@paulinet.de: and that the *hand had kept* that smell for two days. __ 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] Temperature of meteorites
Good morning list. This is actually a good topic for debate and is not so easily answered by simple application of constants. There are several variable factors here that require scrutiny before being able to determine whether the temperature of any given meteorite would / could be hot upon hitting the earth. Thermal conductivity: This is dependent upon the composition of the meteorite and specifically in the metallic percentage of the subject. The internal temperature of a meteor during ablation would be relative to its thermal conductivity, its size and its melting point. If the melting point of an iron /nickel meteor is 1700 degrees, it would obtain a higher core temperature than a stone of the same size with a melting point of 1200 degrees under the same flight conditions. Elevation where ablation is discontinued: During ablation a meteor should be heating through its dominant thermal conductivity. When ablation stops the meteorite should begin to cool through the same conductivity process in reverse. This relates to the amount of time any meteorite is exposed to the effects of heating and cooling. Velocity: This factor is related to the rate of fall and is not necessarily a constant as is commonly repeated. The meteor has a velocity when entering our atmosphere. Atmospheric drag is imposed on the body but is influenced by the type of fall (ie. Stabilized flight or tumbling) and by the body becoming more streamlined (oriented) through the effects of ablation. Comparing two falling objects, higher velocity occurs for greater weight and lower drag coefficient. An oriented meteorite would have a lower drag coefficient and therefore have a higher velocity than a non oriented meteorite of the same weight. This is relative to both the heating and cooling of any given meteorite because of the amount of time (exposure) to these conditions. Flight path of the fall in latitude: The influence here is related to both air temperature and height of the Troposphere. The temperature of any given altitude is directly related to the temperature at sea level at the same latitude. Using a constant of -3 degrees for every 1000 feet rise in elevation, it can be conceived that the temperature at 30,000 feet is different depending upon the season and the location. The troposphere has a lower ceiling over the poles than at the equator and the sea level temperatures in these locations are very different which would produce very different temperatures at 30,000 feet. Remember also as the meteorite gets closer to earth the air temperature is rising in the Troposphere, again by the same factor in reverse (+3degress per 1000 feet). Again the velocity of the meteorite would determine the amount of time the body is heating or cooling. I think it is conceivable under the right circumstances that a meteorite may be warm or hot to the touch when impacting earth. ( I have not built a model using these factors but please feel free) -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Chris Peterson Sent: Tuesday, November 23, 2010 2:14 PM To: Meteorite List Subject: Re: [meteorite-list] Temperature of meteorites Sterling- I think you underestimate the effect of convective heat transfer during cold flight. A fist-sized meteorite might fall for a good three to five minutes through -40°C air, at around 100 m/s. That is long enough for the entire stone to equilibrate to that temperature. In the last minute or so of flight it will generally be in warmer air, and will therefore start to warm up- but probably not to equilibrium. The critical point here is that the meteorite will not maintain an interior temperature similar to its temperature in space. The exception would be a larger stone that remains hypersonic to a lower height, and therefore spends less time in dark flight. We don't really care what the temperature was for the parent's millions of years in space. For any given distance from the Sun, it shouldn't take more than a few days to reach equilibrium, and any meteorite can be assumed to come from a parent that was at 1 AU for that long. So the only real variable is emissivity. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Sterling K. Webb sterling_k_w...@sbcglobal.net To: Meteorite List meteorite-list@meteoritecentral.com Cc: Chris Peterson c...@alumni.caltech.edu; Bernd Pauli bernd.pa...@paulinet.de; Larry Lebofsky lebof...@lpl.arizona.edu; meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 1:18 PM Subject: Re: [meteorite-list] Temperature of meteorites Some points for the debate: The rapid flight through the atmosphere is very brief -- 1-2 seconds. This is not much time to change the temperature of the stone. The rate at which the friction-generated heat is transferred to the interior
Re: [meteorite-list] Temperature of meteorites
Hello all, I've been away from the computer for a couple of days and thought I'd add a couple of other examples. Portales Valley - One of the metal veined stones landed on a blue plastic tarp. The tarp melted where the metal veins of the stone had rested on it. It shouldn't be too difficult to determine a minium temperature that a similar tarp would begin to melt. Malaga - Here's an interesting example I ran across while researching some US falls. A man was searching for Indian artifacts in 1933 in SE New Mexico and was headed back to his car when he observed the following: ...it became dusk by the time he reached the upper terrace, and the sky became overcast with low hanging clouds. While walking with his eye on the horizon ahead of him, watching the crest of the valley wall, be saw a glowing object drop out of the sky, emerging from the clouds and falling, it seemed, not too swiftly, and at an angle somewhat approaching the vertical. It had a reddish appearance, he stated, not unlike a spent ‘Roman Candle,’ becoming less bright as it descended, finally becoming entirely extinguished as it approached the ground. Later the man found a fresh 160 gram chondrite. The stone had abundant metal in it and it was initially mistaken for a mesosiderite. As for cold meteorites, we can't forget Colby that fell on July 4, 1917 and “the man who extracted it from the earth informs me that it was so cold that frost immediately formed on its surface when exposed to the air.” Cheers, Frank From: bernd.pa...@paulinet.de bernd.pa...@paulinet.de To: Meteorite-list@meteoritecentral.com Sent: Tue, November 23, 2010 1:05:42 AM Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ Visit the Archives at http
[meteorite-list] Temperature of meteorites
Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ 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] Temperature of meteorites
Thanks Bernd: This will help a lot! My guess is that warm means warmer than the air temperature, but probably not much warmer than body temperature since even 15 to 20 degrees Centigrade (125 to 135 degrees F) is considered hot. Given that some have been said to be frosty, and one always hears that they are the temperature of space, how many of the hot ones might actually be too cold to handle? Maybe that is the myth! I am very surprised that anything small that has had a chance to cool down in the atmosphere would still be to hot to handle on the ground. I guess I will just have to wait and see my own Fall and pick it up quickly! I wish I could find the old Lost City fall picture of the meteorite in snow. I do not remember seeing any melted snow around it, but it must have been warm enough to attract a dog. Larry Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ 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] Temperature of meteorites
Thanks Bernd. From your data we have as score: warm: 14 versus hot: 8 I believe this can be completed by browsing through other archives or accounts of some recent witnessed falls ? Are there data reporting cold, frozen or alike meteorites ? Take care, Zelimir bernd.pa...@paulinet.de a écrit : Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ 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] Temperature of meteorites
Greetings listees, ahhh the hot/cold debate rears it's head again. I appreciate Bernd's list of falls that seem to indicate warm more so than cold but there are many factors to consider when compiling data. In Bernd's list, how many of these warm specimens were observed by laymen?? Often there are other factors to consider and layman's observations can be often wrong. If a black specimen sits for very long in the sunlight it will absorb warmth and appear warm or hot. Things to consider, Fall dynamics. The space shuttles build up a lot of high heat during decent through the atmosphere. Shuttles have to cool for a while after landing. Meteoroids, depending on their fall speed, only pass through the atmosphere for a short period of time (seconds before dark flight) and don't have suffiecent time to build up heat. The ablating process often removes the molten material as the object falls keeping the specimen more or less at cold space temperature. Catching up or head on collision with Earth effects speed and temperature and fall dynamics. Spinning or stable flight (possible oriented specimen) affects temperature. Size of specimen and retention of cold from space. One thing for certain when thinking about the hot/cold debate. If meteoroids are heated up molten when they fall, then the chemistry would be altered and isotopes reset. Most meteorites don't have high heat alteration from falls or our ability to study them would be impossible. The age would be reset from the heating. The study of meteorites is the study of un-altered specimens from our solar systems past!! I tend to be a cold when they land believer but think a few can come down oriented and there is time for them to absorb some heat from the fall. Nininger investigated several falls seen by laymen that were frosted over but he was efficient at determaining facts based on the story tellers. There are a lot more considerations and facts about falls that are probably still not understood at this time. Fall dynamics are difficult to study unless you have an expert with equipment the second the fall occurs at the site when it happens. My hot and cold worth. --AL Mitterling Mitterling Meteorites __ 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] Temperature of meteorites
I'd be very cautious with reports of perceived meteorite temperatures. How we feel temperature depends on many factors- the actual temperature of the object, of course, but also the temperature of our skin, the ambient air temperature, and perhaps most important, the thermal conductivity of the object. I think that in the majority of cases, the surface of the meteorite will be fairly close to ambient temperature- probably not more than ten degrees either way- which means that people will tend to be very poor estimators of temperature. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: lebof...@lpl.arizona.edu To: bernd.pa...@paulinet.de Cc: meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 3:46 AM Subject: Re: [meteorite-list] Temperature of meteorites Thanks Bernd: This will help a lot! My guess is that warm means warmer than the air temperature, but probably not much warmer than body temperature since even 15 to 20 degrees Centigrade (125 to 135 degrees F) is considered hot. Given that some have been said to be frosty, and one always hears that they are the temperature of space, how many of the hot ones might actually be too cold to handle? Maybe that is the myth! I am very surprised that anything small that has had a chance to cool down in the atmosphere would still be to hot to handle on the ground. I guess I will just have to wait and see my own Fall and pick it up quickly! I wish I could find the old Lost City fall picture of the meteorite in snow. I do not remember seeing any melted snow around it, but it must have been warm enough to attract a dog. Larry __ 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] Temperature of meteorites
I'm not saying that every report is untrustworthy, nor am I saying there aren't a wide range of actual temperatures. I'm just saying that witness reports are almost always the least reliable source of accurate information, and should therefore always be viewed skeptically. Given a long list of reports, I'd expect most to be of low accuracy. Meteoroids in space can easily be too hot to comfortably touch; assuming the Kilbourn was initially large, and the recovered piece was hypersonic to a low altitude (perhaps 10-15 km), I can easily believe it was hot when it landed (although I doubt it was actually warm for three hours). As I noted previously, I don't think there is any such thing as a typical meteorite temperature. While most will probably be not far from ambient, many will still range from below freezing to uncomfortably warm. The wide range of actual temperatures, combined with the many variables that influence perception of temperature, are what create the very different reports we have about falls. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Dark Matter freequa...@gmail.com To: Chris Peterson c...@alumni.caltech.edu Cc: meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 8:21 AM Subject: Re: [meteorite-list] Temperature of meteorites Hi Chris, While I understand your argument, it is just hard to reconcile with reports such as this: Mr. Gaffney picked up the stone, but found it so warm he could hold it only for a second or so. It remained warm nearly three hours. When first picked up it had a straw color on its surface, but gradually assumed a black color. This excerpt is about the Kilbourn meteorite, a beautiful teardrop oriented barn hammerer. Here is my Accretion Desk article on Kilbourn: http://www.meteorite-times.com/Back_Links/2008/july/Accretion_Desk.htm There is a big difference between perceiving something as warm and being too hot to touch. Further, the color change is an interesting connection. Bernd, are there any other references you know of where a freshly fallen meteorite changed color? Cheers, Martin __ 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] Temperature of meteorites (Bernd's List)
I have a couple to add to Bernd's list. Both were picked up immediately after the fall: 23) Lixna: Two other workers who were harrowing a nearby field near the village of Lasdany saw another object covered in earth, which had impacted the ground only 20 steps away. One of the men touched the stone and burned his hand. The burn was later confirmed in a letter by the Count Plater Sieber as he described it as a reddened swollen area on the man's finger... 24) Sena: The fall at Sena took place around noon on November 17, 1773... a man named Miguel Calvo discovered a mysterious stone on the property of his neighbor, Francisco Gonzalez. He first moved it with his hoe and then by hand, but withdrew immediately because the stone was very hot... Sena also occurred long before the acceptance of meteorites and the eruption of Mt. Vesuvius, so there was no reason to be predisposed to any hot rock ideas. Fried ice cream, Mike -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Tuesday, November 23, 2010 1:06 AM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ 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
Re: [meteorite-list] Temperature of meteorites (Bernd's List)
Hi Mike: I am still a fan of cold meteorites (yes I am biased), so is it possible that a burn is due to something very cold rather than hot? Larry I have a couple to add to Bernd's list. Both were picked up immediately after the fall: 23) Lixna: Two other workers who were harrowing a nearby field near the village of Lasdany saw another object covered in earth, which had impacted the ground only 20 steps away. One of the men touched the stone and burned his hand. The burn was later confirmed in a letter by the Count Plater Sieber as he described it as a reddened swollen area on the man's finger... 24) Sena: The fall at Sena took place around noon on November 17, 1773... a man named Miguel Calvo discovered a mysterious stone on the property of his neighbor, Francisco Gonzalez. He first moved it with his hoe and then by hand, but withdrew immediately because the stone was very hot... Sena also occurred long before the acceptance of meteorites and the eruption of Mt. Vesuvius, so there was no reason to be predisposed to any hot rock ideas. Fried ice cream, Mike -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Tuesday, November 23, 2010 1:06 AM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where they found it half-buried and too hot to pick up. 21) Magombedze: A 10-cm stone weighing approximately 600 gr survived the impact intact and was hot to touch. 22) Menziswyl: The farmers say that the stone fell with the lightning and shattered when it hit the ground; it was hot when they picked it up. __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite
[meteorite-list] Temperature of meteorites
Hi, Ursula Marvin has attributed many of the reports of hot stones with a sulphurous smell to a fire and brimstone expectation on the part of the observers, especially for the older historic falls. She notes that the reports of hot stones still exist - primarily due to what observers think a meteorite should be like when it is recovered - but the sulphurous smell seems to have subsided. She references a 1974 paper by Sears. See D.W. Sears, 'Why did meteorites lose their smell?', Journal of the British Astronomical Association 84 (1974), 299-300. See Marvin's chapter Meteorites in History in The History of Meteoritics and Key Meteorite Collections: Fireballs, Falls and Finds, G.J.H. McCall, A. J. Bowden and R. J. Howarth editors (Geological Society, London: 2007), 15-71. Her reference to the hot and sulphurous stones is on page 54. Mark Mark Grossman Briarcliff Manor, NY __ 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] Temperature of meteorites
I recall an objective, quantified study of temperature history in meteorites which proved something about the hot/cold debate and internal temperatures. One of the Martians ( Zagami?) was studied for magnetic domain orientation in that the evidence of a martian paleo-magnetic field might have been preserved. It was. The study relied on the fact that the orientation of magnetite's magnetic domains would be reset if the meteorite had been heated above 165°(c or F ?). They had not if below 5mm What was discovered ,was that the magnetite domains more than 5mm deep had not been reset to Earth's magnetic field. What this says for internal temperature in this meteorite: any and all heat build up to give the surface a hot touch is restricted to roughly a zone 3-5mm deep. The thermal conductivity of silicates is low and as was said ablation is a very effective means of keeping the internal core temperature from rising at the expense of mass raised to the melting point and whisked away. I do believe that iron meteorites, having a higher heat conductivity co-efficient will retain much more re-entry generated heat and could feel warm several minutes. Otherwise I tend to believe the vignette reports such as those of the firemen in New England that reported a rind of frost forming on the broken meteorite as it lay under the dinning room table. Elton - Original Message From: almi...@localnet.com almi...@localnet.com To: meteorite-list@meteoritecentral.com Sent: Tue, November 23, 2010 7:00:11 AM Subject: Re: [meteorite-list] Temperature of meteorites Greetings listees, ahhh the hot/cold debate rears it's head again. I appreciate Bernd's list of falls that seem to indicate warm more so than cold but there are many factors to consider when compiling data. In Bernd's list, how many of these warm specimens were observed by laymen?? Often there are other factors to consider and layman's observations can be often wrong. If a black specimen sits for very long in the sunlight it will absorb warmth and appear warm or hot. Things to consider, Fall dynamics. The space shuttles build up a lot of high heat during decent through the atmosphere. Shuttles have to cool for a while after landing. Meteoroids, depending on their fall speed, only pass through the atmosphere for a short period of time (seconds before dark flight) and don't have suffiecent time to build up heat. The ablating process often removes the molten material as the object falls keeping the specimen more or less at cold space temperature. Catching up or head on collision with Earth effects speed and temperature and fall dynamics. Spinning or stable flight (possible oriented specimen) affects temperature. Size of specimen and retention of cold from space. One thing for certain when thinking about the hot/cold debate. If meteoroids are heated up molten when they fall, then the chemistry would be altered and isotopes reset. Most meteorites don't have high heat alteration from falls or our ability to study them would be impossible. The age would be reset from the heating. The study of meteorites is the study of un-altered specimens from our solar systems past!! I tend to be a cold when they land believer but think a few can come down oriented and there is time for them to absorb some heat from the fall. Nininger investigated several falls seen by laymen that were frosted over but he was efficient at determaining facts based on the story tellers. There are a lot more considerations and facts about falls that are probably still not understood at this time. Fall dynamics are difficult to study unless you have an expert with equipment the second the fall occurs at the site when it happens. My hot and cold worth. --AL Mitterling Mitterling Meteorites __ 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] Temperature of meteorites (Bernd's List)
I recall the Navarro house hammering stone of Park Forest reported as being almost too hot to touch. I believe her name was Toby Navarro but I may be wrong. She was actually working at her computer when the stone crashed through the roof, smashed a computer and hit a game box. She picked it up within seconds of it demolishing the room and told us that it smelt like an oven and was uncomfortable to touch due to heat. I have no reason to doubt her whatsoever. She is very religious and a person of honor. Mike Farmer purchased the stone after spending a morning in church with her as she prayed for guidance on how to deal with the stone. I offered her much more than Mike had but she had already made up her mind to sell it to him since Mike took the time to prayer with her and talk to her congregation. I was wondering what happened to Mike that morning since he was missing for 4 hours. Oh Well, you can't win them all. Best Regards, Adam . - Original Message From: lebof...@lpl.arizona.edu lebof...@lpl.arizona.edu To: Mike Bandli fuzzf...@comcast.net Cc: bernd.pa...@paulinet.de; meteorite-list@meteoritecentral.com Sent: Tue, November 23, 2010 9:13:36 AM Subject: Re: [meteorite-list] Temperature of meteorites (Bernd's List) Hi Mike: I am still a fan of cold meteorites (yes I am biased), so is it possible that a burn is due to something very cold rather than hot? Larry I have a couple to add to Bernd's list. Both were picked up immediately after the fall: 23) Lixna: Two other workers who were harrowing a nearby field near the village of Lasdany saw another object covered in earth, which had impacted the ground only 20 steps away. One of the men touched the stone and burned his hand. The burn was later confirmed in a letter by the Count Plater Sieber as he described it as a reddened swollen area on the man's finger... 24) Sena: The fall at Sena took place around noon on November 17, 1773... a man named Miguel Calvo discovered a mysterious stone on the property of his neighbor, Francisco Gonzalez. He first moved it with his hoe and then by hand, but withdrew immediately because the stone was very hot... Sena also occurred long before the acceptance of meteorites and the eruption of Mt. Vesuvius, so there was no reason to be predisposed to any hot rock ideas. Fried ice cream, Mike -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Tuesday, November 23, 2010 1:06 AM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour
Re: [meteorite-list] Temperature of meteorites (Bernd's List)
Herr Professor and List, Could the black fusion crust formed at the time of ablation absorb the sun's radiative heat during the dark flight fall? Or provide some form of insulating benefit? Count Deiro IMCA 3536 -Original Message- From: lebof...@lpl.arizona.edu Sent: Nov 23, 2010 9:13 AM To: Mike Bandli fuzzf...@comcast.net Cc: bernd.pa...@paulinet.de, meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Temperature of meteorites (Bernd's List) Hi Mike: I am still a fan of cold meteorites (yes I am biased), so is it possible that a burn is due to something very cold rather than hot? Larry I have a couple to add to Bernd's list. Both were picked up immediately after the fall: 23) Lixna: Two other workers who were harrowing a nearby field near the village of Lasdany saw another object covered in earth, which had impacted the ground only 20 steps away. One of the men touched the stone and burned his hand. The burn was later confirmed in a letter by the Count Plater Sieber as he described it as a reddened swollen area on the man's finger... 24) Sena: The fall at Sena took place around noon on November 17, 1773... a man named Miguel Calvo discovered a mysterious stone on the property of his neighbor, Francisco Gonzalez. He first moved it with his hoe and then by hand, but withdrew immediately because the stone was very hot... Sena also occurred long before the acceptance of meteorites and the eruption of Mt. Vesuvius, so there was no reason to be predisposed to any hot rock ideas. Fried ice cream, Mike -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Tuesday, November 23, 2010 1:06 AM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object, which had embedded itself in a straightdownward course for 13 inches, was found to be quite hot, continuing so for about an hour. 16) Eichstädt: The man rushed to the spot but found the black stone too hot to pick up until it cooled in the snow. 17) Hanau: A hot stone the size of a pea was picked up, weight 0.37 gr. 18) Harrogate: A hot stone, like basalt, fell accompanied by whistling in the air and lightning and thunder ... 19) Holbrook: One piece larger than an orange fell into a tree in a yard at Aztec cutting the limb off slick and clean and falling to the ground, and when picked up was almost red-hot. Von Achen, who saw them fall, reported that they were too hot to pick up. Two accounts state that they became lighter in color after cooling. 20) Lucé: several harvesters, startled by sudden thunderclaps and a loud hissing noise, looked up and saw the stone plunge into a field where
Re: [meteorite-list] Temperature of meteorites (Bernd's List)
A dark crust certainly will absorb energy from the Sun during the fall. But that radiative energy gain is going to be a lot smaller than the convective loss from a stream of -40° air blowing across the stone at 100 m/s or so! I'd think a smooth fusion crust would actually provide better heat transfer than a rougher surface. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Count Deiro countde...@earthlink.net To: lebof...@lpl.arizona.edu; Mike Bandli fuzzf...@comcast.net Cc: bernd.pa...@paulinet.de; meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 10:53 AM Subject: Re: [meteorite-list] Temperature of meteorites (Bernd's List) Herr Professor and List, Could the black fusion crust formed at the time of ablation absorb the sun's radiative heat during the dark flight fall? Or provide some form of insulating benefit? Count Deiro __ 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] Temperature of meteorites (Bernd's List)
Could the black fusion crust formed at the time of ablation absorb the sun's radiative heat during the dark flight fall? Or provide some form of insulating benefit? Maybe...but I'd think that the air it has to pass thru during this period would be quite cold and its passing thru would cool the outside skin quite quickly. The meteorite at this period would be cold on the inside and getting cold on the thin skin outside. GeoZay __ 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] Temperature of meteorites (Bernd's List)
Hi Larry, is it possible that a burn is due to something very cold rather than hot? Absolutely! There's the trick with the old clothes iron. Stick it in the freezer for a couple hours, take it out and tell someone to touch it. They'll say it is HOT! Of course, this is the perception of how they expect something should feel, which could be similar with fresh meteorites. What I still find interesting, though, is Sena. At that time, no one understood what a meteorite was and it was pre-Vesuvius eruption (theories of volcanic stones falling from the sky). To this man, it was simply a rock that appeared on the ground and was hot. He had no reason to embellish or lie and knew nothing of fiery meteors. Was it hot or was it really cold. We'll never really know. In the end, I think both hot and cold stones are possible, though it is interesting to note all of the historic falls with tales of heat. -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited. -Original Message- From: lebof...@lpl.arizona.edu [mailto:lebof...@lpl.arizona.edu] Sent: Tuesday, November 23, 2010 9:14 AM To: Mike Bandli Cc: bernd.pa...@paulinet.de; meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Temperature of meteorites (Bernd's List) Hi Mike: I am still a fan of cold meteorites (yes I am biased), so is it possible that a burn is due to something very cold rather than hot? Larry I have a couple to add to Bernd's list. Both were picked up immediately after the fall: 23) Lixna: Two other workers who were harrowing a nearby field near the village of Lasdany saw another object covered in earth, which had impacted the ground only 20 steps away. One of the men touched the stone and burned his hand. The burn was later confirmed in a letter by the Count Plater Sieber as he described it as a reddened swollen area on the man's finger... 24) Sena: The fall at Sena took place around noon on November 17, 1773... a man named Miguel Calvo discovered a mysterious stone on the property of his neighbor, Francisco Gonzalez. He first moved it with his hoe and then by hand, but withdrew immediately because the stone was very hot... Sena also occurred long before the acceptance of meteorites and the eruption of Mt. Vesuvius, so there was no reason to be predisposed to any hot rock ideas. Fried ice cream, Mike -- Mike Bandli Historic Meteorites www.HistoricMeteorites.com and join us on Facebook: www.facebook.com/Meteorites1 IMCA #5765 --- -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Tuesday, November 23, 2010 1:06 AM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Temperature of meteorites Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed
Re: [meteorite-list] Temperature of meteorites
Some points for the debate: The rapid flight through the atmosphere is very brief -- 1-2 seconds. This is not much time to change the temperature of the stone. The rate at which the friction-generated heat is transferred to the interior of the stone is determined by the thermal conductivity of that rock, and rock's thermal conductivity is very low, so low that virtually none of the heat will affect temperatures deeper than a few millimeters or a centimeter into the stone. Most of that heat generated by friction on the outer surface goes into melting rock which is then is removed from the meteorite by on-going ablation. The molten material stripped from the stone takes that heat with it as it becomes the particles in the trail (which have their own thermal evolution that does not affect the stone). Only a small fraction is wasted by warming the stone itself. That said, thermal equilibrium of the stone is likely achieved (or nearly) within a very short time once it lands. Its temperature will be more-or-less whatever it was before it encountered this obstructive planet. Apart from some rough treatment of the surface, the stone's temperature is the same as it always was. So, what temperature WAS the meteoroid in the many thousands or millions of years that it orbited the sun? That depends on what its orbit was, or more precisely, WHERE its orbit was and its emissivity and reflectivity and so on. Take a look at the following chart of Meteoroid Temperature vs. Solar Distance, supplied by MexicoDoug: http://www.diogenite.com/met-temp.html It is a model derived from fairly complete and reasonable assumptions, which were discussed on this List long ago: http://six.pairlist.net/pipermail/meteorite-list/2005-January/007521.html This is the first of three parts; follow the links for #2 and #3. Those with more factors to include are welcome to refine the model, I'm sure. Sterling K. Webb - - Original Message - From: lebof...@lpl.arizona.edu To: bernd.pa...@paulinet.de Cc: meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 4:46 AM Subject: Re: [meteorite-list] Temperature of meteorites Thanks Bernd: This will help a lot! My guess is that warm means warmer than the air temperature, but probably not much warmer than body temperature since even 15 to 20 degrees Centigrade (125 to 135 degrees F) is considered hot. Given that some have been said to be frosty, and one always hears that they are the temperature of space, how many of the hot ones might actually be too cold to handle? Maybe that is the myth! I am very surprised that anything small that has had a chance to cool down in the atmosphere would still be to hot to handle on the ground. I guess I will just have to wait and see my own Fall and pick it up quickly! I wish I could find the old Lost City fall picture of the meteorite in snow. I do not remember seeing any melted snow around it, but it must have been warm enough to attract a dog. Larry Good morning Listees, Listoids, Listers, Here's a copy of something I posted many years ago (maybe 2004). Cheers, Bernd --- Meteorites - warm or hot to the touch? 01) The Binningup meteorite was recovered within a few minutes of the fall and was reported to have been warm to the touch. 02) Cabin Creek: Three hours after the fall, Mr. and Mrs. Shandy were able to find the hole and excavate the mass, reportedly still uncomfortably warm. 03) Glatton: was warm, not hot, when first picked up. 04) Gurram Konda: near the tent some small warm stones, which the Sentry has seen falling down. 05) Juromenha: The mass was said to have been incandescent when discovered and still warm when recovered next morning 06) L'Aigle: Affrighted persons who picked them up found the stones to be very warm and smelling of sulfur. 07) Limerick: It was immediately dug up, and I have been informed by those that were present, and on whom I could rely, that it was then warm and had a sulphurous smell. 08) Middlesbrough: The stone was new-milk warm when found, ... 09) Noblesville: The meteorite was not glowing as it passed the boys and was slightly warm when Spaulding picked it up a few seconds after it fell. 10) Pettiswood: The affrighted horse fell to the Earth, and two boys rushed to him in terror carrying fragments that Bingley found to be warm as milk just from the cow. 11) Pontlyfni: When I picked up the fragment of metal, or whatever it is, it was warm in my hand. 12) Rowton: It is, moreover, stated that when Mr. Brooks found the mass it was quite warm. 13) Tsukuba: Seconds later student Ryutaro Araki stopped to retrieve a still-warm stone that had fallen in front of his car near Tsukuba 14) Wold Cottage: Rushing to the spot he found a large stone, warm and smoking and smelling of sulfur. 15) Crumlin: When dug out the object
Re: [meteorite-list] Temperature of meteorites
Sterling- I think you underestimate the effect of convective heat transfer during cold flight. A fist-sized meteorite might fall for a good three to five minutes through -40°C air, at around 100 m/s. That is long enough for the entire stone to equilibrate to that temperature. In the last minute or so of flight it will generally be in warmer air, and will therefore start to warm up- but probably not to equilibrium. The critical point here is that the meteorite will not maintain an interior temperature similar to its temperature in space. The exception would be a larger stone that remains hypersonic to a lower height, and therefore spends less time in dark flight. We don't really care what the temperature was for the parent's millions of years in space. For any given distance from the Sun, it shouldn't take more than a few days to reach equilibrium, and any meteorite can be assumed to come from a parent that was at 1 AU for that long. So the only real variable is emissivity. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Sterling K. Webb sterling_k_w...@sbcglobal.net To: Meteorite List meteorite-list@meteoritecentral.com Cc: Chris Peterson c...@alumni.caltech.edu; Bernd Pauli bernd.pa...@paulinet.de; Larry Lebofsky lebof...@lpl.arizona.edu; meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 1:18 PM Subject: Re: [meteorite-list] Temperature of meteorites Some points for the debate: The rapid flight through the atmosphere is very brief -- 1-2 seconds. This is not much time to change the temperature of the stone. The rate at which the friction-generated heat is transferred to the interior of the stone is determined by the thermal conductivity of that rock, and rock's thermal conductivity is very low, so low that virtually none of the heat will affect temperatures deeper than a few millimeters or a centimeter into the stone. Most of that heat generated by friction on the outer surface goes into melting rock which is then is removed from the meteorite by on-going ablation. The molten material stripped from the stone takes that heat with it as it becomes the particles in the trail (which have their own thermal evolution that does not affect the stone). Only a small fraction is wasted by warming the stone itself. That said, thermal equilibrium of the stone is likely achieved (or nearly) within a very short time once it lands. Its temperature will be more-or-less whatever it was before it encountered this obstructive planet. Apart from some rough treatment of the surface, the stone's temperature is the same as it always was. So, what temperature WAS the meteoroid in the many thousands or millions of years that it orbited the sun? That depends on what its orbit was, or more precisely, WHERE its orbit was and its emissivity and reflectivity and so on. Take a look at the following chart of Meteoroid Temperature vs. Solar Distance, supplied by MexicoDoug: http://www.diogenite.com/met-temp.html It is a model derived from fairly complete and reasonable assumptions, which were discussed on this List long ago: http://six.pairlist.net/pipermail/meteorite-list/2005-January/007521.html This is the first of three parts; follow the links for #2 and #3. Those with more factors to include are welcome to refine the model, I'm sure. __ 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] Temperature of meteorites
I was under the impression that it's a myth that direct friction from O and N molecules on the surface of a meteorite create the heat that causes ablation. I thought that ram pressure in front of the meteorite was the main factor in generating heat. The KE and PE would create a hot shock layer which would flow back around the meteorite causing its outer layer to melt. I would think that friction is a minor factor, unless you're talking about ram pressure as a kind of friction. Phil Whitmer --- Some points for the debate: The rapid flight through the atmosphere is very brief -- 1-2 seconds. This is not much time to change the temperature of the stone. The rate at which the friction-generated heat is transferred to the interior of the stone is determined by the thermal conductivity of that rock, and rock's thermal conductivity is very low, so low that virtually none of the heat will affect temperatures deeper than a few millimeters or a centimeter into the stone. Most of that heat generated by friction on the outer surface goes into melting rock which is then is removed from the meteorite by on-going ablation. The molten material stripped from the stone takes that heat with it as it becomes the particles in the trail (which have their own thermal evolution that does not affect the stone). Only a small fraction is wasted by warming the stone itself. That said, thermal equilibrium of the stone is likely achieved (or nearly) within a very short time once it lands. Its temperature will be more-or-less whatever it was before it encountered this obstructive planet. Apart from some rough treatment of the surface, the stone's temperature is the same as it always was. So, what temperature WAS the meteoroid in the many thousands or millions of years that it orbited the sun? That depends on what its orbit was, or more precisely, WHERE its orbit was and its emissivity and reflectivity and so on. Take a look at the following chart of Meteoroid Temperature vs. Solar Distance, supplied by MexicoDoug: http://www.diogenite.com/met-temp.html It is a model derived from fairly complete and reasonable assumptions, which were discussed on this List long ago: http://six.pairlist.net/pipermail/meteorite-list/2005-January/007521.html This is the first of three parts; follow the links for #2 and #3. Those with more factors to include are welcome to refine the model, I'm sure. Sterling K. Webb - __ 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] Temperature of meteorites
Heating is due to ram pressure for bodies larger than a few millimeters. For very small particles, ram pressure is not a factor because of the large distance between air molecules compared with the cross-sectional area. These small particles do heat up as the result of collisions with molecules, in a process that is analogous to friction. In other words, for all bodies that produce meteorites, frictional heating effects are insignificant. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: JoshuaTreeMuseum joshuatreemus...@embarqmail.com To: meteorite-list@meteoritecentral.com Sent: Tuesday, November 23, 2010 2:22 PM Subject: [meteorite-list] Temperature of meteorites I was under the impression that it's a myth that direct friction from O and N molecules on the surface of a meteorite create the heat that causes ablation. I thought that ram pressure in front of the meteorite was the main factor in generating heat. The KE and PE would create a hot shock layer which would flow back around the meteorite causing its outer layer to melt. I would think that friction is a minor factor, unless you're talking about ram pressure as a kind of friction. Phil Whitmer __ 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] Temperature of meteorites
Hi all: I am in the middle of a workshop on asteroids and meteorites. At the end of the first day, the teachers get to write down questions that they would like answered. During the session, I had said that when they land, meteorites are cold, not burning hot. The question that was asked was how cold? What is the best estimate we have for the ambient temperature of meteorites after they have passed through the atmosphere? Thanks. Larry __ 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] Temperature of meteorites
Hello Larry and List, What is the best estimate we have for the ambient temperature of meteorites after they have passed through the atmosphere? Dhurmsala was said (!) to have had frost on its surface when it was recovered. Cheers, 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
Re: [meteorite-list] Temperature of meteorites
Hi, after glowing off, the small size meteorites passes thru Stratosphere with temperatures of minus 60 °C in winter and -10°C in summer. During their minute-flight thru the atmophere they warm up to normal temperature. Only large objects which fly til the ground with hight supersonic speed (like Sikhote Alin) contact the ground with temperatures above 500°C. What I will say, the temperature depends on the landing speed. If it is the normal velocity of fall of earth gravity the meteorite is cold, if it is supersonic speed, it could be very hot. m42protosun -Original-Nachricht- Subject: [meteorite-list] Temperature of meteorites Date: Tue, 23 Nov 2010 00:34:24 +0100 From: lebof...@lpl.arizona.edu To: Chris Peterson c...@alumni.caltech.edu Cc: meteorite-list@meteoritecentral.com Hi all: I am in the middle of a workshop on asteroids and meteorites. At the end of the first day, the teachers get to write down questions that they would like answered. During the session, I had said that when they land, meteorites are cold, not burning hot. The question that was asked was how cold? What is the best estimate we have for the ambient temperature of meteorites after they have passed through the atmosphere? Thanks. Larry __ 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 Sammle all Deine Mails in einem Postfach! Jetzt kostenlose E-Mail Adresse @t-online.de einrichten und alles auf einen Blick haben. http://www.t-online.de/email-umzug __ 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] Temperature of meteorites
I don't think there is a general answer to that question. It depends heavily on the size of the body after ablation. The larger it is, the longer it will take to cool down as it falls for a few minutes through cold (around -40°C) air. So a large body will be closer to the temperature it was at in space, which might be anywhere from 50°C or so down to a few tens of degrees below zero. Further complicating things, the outer surface might be near ambient temperature, while the interior is much cooler (or occasionally warmer). The few reports I've heard of meteorites forming frost after they fell were in cases where they split open. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: lebof...@lpl.arizona.edu To: Chris Peterson c...@alumni.caltech.edu Cc: meteorite-list@meteoritecentral.com Sent: Monday, November 22, 2010 4:34 PM Subject: Temperature of meteorites Hi all: I am in the middle of a workshop on asteroids and meteorites. At the end of the first day, the teachers get to write down questions that they would like answered. During the session, I had said that when they land, meteorites are cold, not burning hot. The question that was asked was how cold? What is the best estimate we have for the ambient temperature of meteorites after they have passed through the atmosphere? Thanks. Larry __ 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] Temperature of meteorites
Are there ANY photos of any meteorite, taken *immediately* after it fell? Within seconds, or even minutes? I know some people have reported meteorites as warm, (e.g. Peekskill). http://astro.wsu.edu/worthey/astro/html/im-meteor/strikes.html and http://www.amnh.org/exhibitions/permanent/meteorites/what/index.php Then this: http://www.mail-archive.com/meteorite-list@meteoritecentral.com/msg42288.html and I'm sure there are others... So is it that all meteorite falls are different and variable with regards to temperature at the time of fall and is this why there is no definitive answer to the Hot/Cold question? Is it because some are warm, and some are cold? Does it depend on angle of descent, speed, and composition of the body? All of the above? Does the weather/temperature in the area of the fall have anything to do with the temperature of the meteorite at the time of impact? Lots of questions to ponder... Regards, Eric On 11/22/2010 3:36 PM, bernd.pa...@paulinet.de wrote: Hello Larry and List, What is the best estimate we have for the ambient temperature of meteorites after they have passed through the atmosphere? Dhurmsala was said (!) to have had frost on its surface when it was recovered. Cheers, 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 __ 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
