[meteorite-list] Hot vs Cold again...wasmMeteorite Crashes Through Thailand House Roof

From: MEM <mstreman53_at_meteoritecentral.com>
Date: Wed, 29 Jun 2016 01:04:58 +0000 (UTC)
Message-ID: <232637969.637305.1467162298146.JavaMail.yahoo_at_mail.yahoo.com>

This was looked into several times in the list history. I am recalling details from those discussions/my research.

Any body arriving from space is at least -60?c and closer to -120?c to -180?c based on some black body studies of asteroids-- IIRC


The temperature at the air-meteoroid boundary of entry exceeds the melting point of both iron and olivine. Most of that heat is carried off as an iron/silicate mist. Each mili-second of incandescent flight an entirely new surface is formed. Inward traveling heat is being stripped away almost as fast as it is penetrating in low thermo-conducivity but much faster in high conductivity bodies (e.g iron). The radiative cooling during dark flight is probably calculable and a missing factor in estimating the state of heat content upon landing.


One of the Weston CT meteorites formed a frost rind shortly after falling after sufficient time for all reentry heat to dissipate. I do not recall any other comments. This was discovered by a fireman under the dining table. I do not recall which other meteorite it was but, another was noted to have a frost rind after a few minutes. Other falls such as Sylacaga are silent as to the temperature.


Conclusions:

An immediately-recovered, newly-fallen silicate/stony meteorite is usually--but briefly "hot/uncomfortably warm" to the touch. The rind is very hot but lacks much heat reservoir. Heat penetration--based on measuring heated rims-- is somewhere between 2mm but not more than 6mm. Beyond 6mm does not get above 140? F proven by the domain reset of magnetite orientation in Martian Meteorites. Be it remembered that an empty .50 cal brass case "feels" like it would burn you if it goes down one's shirt but lacks the heat content to cause burns.


Specific characterizations of hot/warm are hidden among the various accounts of some well known falls nearby humans. Monahans, Mbale, Allende, Murchison etc.. If you disagree-- don't start some silly list fight--Do your own weeks of research reach your own conclusions!


Iron meteorites owing to a high coefficient of therm-conductivity are likely very hot to the touch and warm throughout. It is probably much like a piece of metal cut by a welding torch--no sign of bluing but very hot on the opposite end of the cut.



Elton
Received on Tue 28 Jun 2016 09:04:58 PM PDT