[meteorite-list] Cali chondrite fell extremely cold!

[Alexander Seidel]

Mike, your comment was obviously triggered by my earlier post to the list this day. I always thought stones of a meteorite fall would be rather "cold" after touchdown. Then again one has to look at typical equilibrium temps for a tumbling stone meteoroid at a typical Earth orbit cruising distance before encounter with the Earth atmosphere. There were several posts about this on the list in the past, may be someone can retrieve them from the archives. The hot phase of atmospheric entry, before reaching the retardation point, will most likely only affect the very outer zones of a meteoroid large enough to not disintegrate, while the inner parts will remain effectively at the former equilibriums temps due to a rather low heat transfer process for typical stony meteorites in the few seconds or minutes of atmospheric transit. And the final dark flight will cool down the former temporary high temps on the outsides of the stone pretty soon.

If I ever had the chance to pick up a freshly fallen stone immediately after the event, I would expect it to be rather "cold" to the touch.... :)

Alex
Berlin/Germany

-------- Original-Nachricht --------
Datum: Sat, 28 Jul 2007 18:33:24 -0700 (PDT)
Von: Michael Farmer <meteoriteguy at yahoo.com>
An: meteorite-list at meteoritecentral.com
Betreff: [meteorite-list] Cali chondrite fell extremely cold!

> Ok, here is a good starting discussion topic for this
> meteorite fall. 
> We had  people in two of the four homes hit who picked
> up the meteorites within seconds of the impact.
> Cali#003 and Cali#004. Both people said that the
> pieces were very cold, so cold they quickly put them
> down. These people live near the equator, so the
> meteorites must have been quite cold.
> How many other meteorites have been reported to be
> very cold? I know that Hvittis and St Michel if I
> recall were said to have frost on them almost
> immediately after the fall, is that correct?
> Michael
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