[meteorite-list] Molten Core? Solid Core? Rocky Core? Blue Cheese!?

From: Richard Kowalski <*damoclid_at_meteoritecentral.com*> Date: Tue, 29 Dec 2009 20:09:39 -0800 (PST) Message-ID: <636421.43410.qm_at_web113606.mail.gq1.yahoo.com> · damoclid_at_meteoritecentral.com

--
Richard Kowalski
http://fullmoonphotography.net
IMCA #1081
--- On Tue, 12/29/09, Meteorites USA <eric at meteoritesusa.com> wrote:
> From: Meteorites USA <eric at meteoritesusa.com>
> Subject: [meteorite-list] Molten Core? Solid Core? Rocky Core? Blue Cheese!?
> To: meteorite-list at meteoritecentral.com
> Date: Tuesday, December 29, 2009, 9:02 PM
> OK,
> 
> A friend and I were watching a show on Discovery or NatGeo
> a couple months back. The program I think was about
> asteroids, and impacts, perhaps even "How the Earth Was
> Made" or another program. Don't really remember....
> 
> The point is during the show they said very
> matter-of-factly on three separate occasions that the
> Earth's core was made of three different materials. One
> scientist (or narrator I don't remember)? said Earth
> had a rocky core. Which we laughed at of course because we
> all know that the Earth's core is Solid iron right? Then
> another scientist confirmed our knowledge and stated what we
> already knew. The Earth core is made of SOLID iron. "Of
> course we said!" Now that's right... Then not 10 minutes
> more into the show another person stated that the Earth had
> a molten iron core.
> 
> To make matters even more confusing the show went on to say
> that the SOLID iron core was surrounded by molten iron with
> lighter "rocky" materials "floating" out beyond that OK...
> sounded good at the time, but....
> 
> My question is simple. Which is it? Molten? Solid Iron? or
> Solid iron surrounded by molten iron. And if it's the latter
> how is this possible? Wouldn't the solid iron core NOT be
> solid if it were sitting in the middle of a molten lake of
> iron? Does the core cool faster than the surrounding
> material, and if so how is this possible considering this
> the logic that says an object cools from the outside in.
> 
> Now, I'd like to stop there but I just read an interesting
> article on National Geographic's website titled "North
> Magnetic Pole Moving East Due to Core Flux" here:
> http://news.nationalgeographic.com/news/2009/12/091224-north-pole-magnetic-russia-earth-core.html
> 
> At the end of the article it flatly states:
> 
> "...Wandering Pole -
> 
> Geologists think Earth has a magnetic field because the
> core is made up of a solid iron center surrounded by rapidly
> spinning liquid metal. This creates a "dynamo" that drives
> our magnetic field.
> 
> Scientists had long suspected that, since the molten core
> is constantly moving, changes in its magnetism might be
> affecting the surface location of magnetic north...."
> 
> I don't know about you, but this confuses me just a little
> bit...
> 
> Can anyone please clear this up for me? And perhaps the
> rest of the world? ;)
> 
> Regards,
> Eric Wichman
> Meteorites USA
> 
> 
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