[meteorite-list] Do all meteorites have nickel

[Göran Axelsson]

Since I haven't seen any answers on this post I'll take a guess.
Let's see how far away I am.

I would guess that the only meteorites that have a substantial part nickel
is the ones with free metal inside. In Lunar and Martian meteorites it
should be as uncommon as in earth rocks.
As I understand it, one way to identify meteorites is to look for effects
of cosmic radiation. Some isotopes are a part of cosmic radiation
and the supply is cut off when the atmosphere shields it on the ground.
That way you could not only decide it's been in space. You could also
decide when it was blasted off the mother planet... at least with Mars,
how long it's been in space and an approximate time when it hit Earth.
http://calspace.ucsd.edu/marsnow/library/science/mars_meteorites1.html

Ratio between oxygen isotopes could also be used, even though the
Moon and the Earth have the same composition.

Now it isn't always this simple as we saw free metal in that last
Lunar meteorite. Which isn't too surprising given the bombardment
of meteorites the surface have got during the last 4000 million years.

/Göran

Tom Knudson wrote:

> Hi List, do all meteorites have nickel to some degree, even Lunar and 
> Martian meteorites?  If not, how do they determine it's a meteorite, 
> seems to me like they test it for Nickel and if there is none, it is 
> goes no further?
>
>
> Thanks, Tom
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