[meteorite-list] Re Cu meteorite

From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Sat, 12 Jul 2008 11:10:04 -0600
Message-ID: <188e01c8e442$289a6280$0a01a8c0_at_bellatrix>

The fact that there are no copper meteorites is most likely because the
processes involved in asteroid formation didn't allow metallic copper to
accumulate in bulk. But if it did, there's no reason that pure copper
meteorites wouldn't survive to the ground. Like any other meteorite, the
interior would not heat significantly. As long as the body was large enough
to avoid ablating away before slowing down, you could expect a meteorite.

It turns out that even a big block of ice can survive passage through the
atmosphere. The outside ablates away, the interior never warms up.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message -----
From: "Pete Shugar" <pshugar at clearwire.net>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, July 11, 2008 11:16 PM
Subject: [meteorite-list] Re Cu meteorite


> Greeting list,
> I am by no means an expert. From all that I've read from this fine list of
> experts
> and scientists, meteorites come in several packages, i.e., irons,
> stony-irons and
> stonys. (I'm keeping it simple.)
> I haven't ever heard mentioned of a meteorite composed of copper.
> Now, copper I know. This is because I've a degree in electronics.
> Gold and silver make better conductors than copper, but are too expensive
> to be used except in very special and limited circumstances.
> Copper is a very malleable substance which has a melting point of 1984.32
> Deg F
> and a boiling point of 4643 Deg F.
> Several of the list's scientists and other knowledgeable persons on the
> list
> have tossed out
> figures that are much higher than this as heat levels generated upon entry
> into our earth's
> atmosphere.
> Again, I am no expert when it comes to the mechanics of earth accreting
> material from
> the depths of space, but it would seem just near impossible for a meteor
> composed of
> mostly copper to survive til it smacked into the ground (which would
> change
> the remaining
> kinetic energy into yet more heat).
> All this to say that copper is just not likely to be a meteorite. I do
> suppose that if it started
> out as a large enough chunk it might be possible to survive til impact.
> I've read numerous pieces on asteroids and none are mention as being
> thought
> to be made out of
> primarily copper or show the reflected light spectrum of copper.
> There are many meteorites listed in the Met Bull as having small
> percentages
> of copper.
> None have large to almost exclusive amounts of copper.
> I have to agree with Sterling and say that it was most likely something (a
> bushing?)
> made of copper that fell from an aircraft.
> In conclusion, if a copper meteorite existed, I would also look for one
> made
> of lead, or even gold or silver
> for that matter but I fear it would share the same fate as the copper
> meteorite.
> As a side note, Sterling, maybe there was a gold and a silver meteorite
> that
> broke up over
> the Ohio and Kentucky area and that's where all the precious metals came
> from.
>
> Pete
Received on Sat 12 Jul 2008 01:10:04 PM PDT