[meteorite-list] NWA 2999 - A Case for Mercury? or not?

From: star-bits_at_comcast.net <star-bits_at_meteoritecentral.com>
Date: Tue Dec 20 17:44:54 2005
Message-ID: <122020052244.5613.43A8895D0006E90B000015ED22007610649C9B070DD39D0E9B9C_at_comcast.net>

Michael Fowler wrote:

<Dr. Irving's proposal certainly allows for a more rapid cooling of Mercury, but perhaps not a sufficiently rapid cooling. Even if it allowed cooling 20 times faster, that would only compress a billion year time scale down to 50 million years, not quick enough by far.>


      Mike I think you have misunderstood the process a bit. Only 2 things are required (1) the body has to have time (and mass) to differentiate and (2) the sample analyzed has to solidify. Once it is solidified the age information is locked in unless it undergoes further thermal or shock metamorphosis. Half the planet could still be in the magma ocean state and it wouldn't matter to the age of that sample.
      It is highly unlikely that any meteorite will be attributed to Mercury with any certainty until a probe reaches the surface and does some isotopic analysis. That is something I am beginning to doubt I will see in my lifetime.

--
Eric Olson
ELKK Meteorites
http://www.star-bits.com
Received on Tue 20 Dec 2005 05:44:45 PM PST


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