[meteorite-list] more data
From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Mon, 3 Dec 2007 10:23:48 -0700 Message-ID: <012b01c835d1$4b045030$0a01a8c0_at_bellatrix> Ferromagnetic materials retain a net magnetic moment after exposure to a magnetic field. Paramagnetic materials do not, even though they are similarly attracted to magnets. Both iron and nickel, the primary constituents in magnetic meteorites, are highly ferromagnetic. However, unless they have been exposed to a very strong field, the crystalline nature of the material means that the magnetism is confined to many small domains, which cancel each other out. So you don't see much magnetism in meteorites at a macro scale. Not because the magnetism has been lost, but because it probably never existed. The interior of a meteorite never comes close to the curie temperature of iron or nickel during entry. An meteorite will have the same magnetic properties on the ground that it had in space (other than the outer millimeter or so). Chris ***************************************** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com ----- Original Message ----- From: "Peter A Shugar" <pshugar at clearwire.net> To: <Meteorite-list at meteoritecentral.com> Sent: Monday, December 03, 2007 9:59 AM Subject: [meteorite-list] more data > Mike, > Consider this. When the meteorite or iron comes into the magnetic > field of > the magnet, it is attracted > to the magnet. This could be construed as the first stroke of the > piece on > the magnet. The piece needs to be stroked in the same direction a > number of > times to become a magnet, so with only the "one" stroke, > it would leave the piece very slightly magnetic !! > Magnetite is a naturally occurring mineral that is already magnetic. > It's > attracted to the magnet,and the orientation of the magnetite will be > such > that its polarity is the opposite of the pole on the magnet. > As to the 'slightly magnetic" meteorite, remember the above, it's the > first > "stroke". > Also, the heat of the entry into the atmosphere will kill any > magnetism of > the meteorite. > Lastly, the shock of the material being ejected from the parent body > will > also kill the magnetism. > This can be demonstrated by simply taking a magnet and bashing it very > , > very hard with a sledge hammer. > The one blow may not kill all the magnetism, but it surely will be a > weaker > magnet. > This causes the aligned molecules of the magnet to be scrambled, thus > destroying the magnet. > Naturally occurring magnetic meteorite----No. > Pete Received on Mon 03 Dec 2007 12:23:48 PM PST |
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