[meteorite-list] Super-heavy elements in meteorites?

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Mon, 12 Jul 2010 16:31:53 -0500
Message-ID: <2916A1E5942B4393B90EE5C1964C66A0_at_ATARIENGINE2>

It's not the atomic number of a hypothetical
superheavy element that matters so much as
the number of neutrons and protons in the
nucleus.

Particles are forced to assemble in "shells"
according to their quantum properties. Electrons
assemble in shells, too. Helium with 2 electrons
has filled the innermost electron shell with the
two it will hold. This is a "magic number." The
next shell holds 8 electrons, for a total of ten
(neon), another magic number, and so on.

The next electron shell has eight also, the next two
shells 18, and then 32... The elements with electron
magic numbers are the noble gases. But nuclei are
not so simple; the numbers are based on theory.
The theory has "fuzzy edges" and lots of wrinkles.

The nucleus of the atom has magic numbers of both
protons and neutrons. This a much hairer calculation
than with those little electrons. Each of the protons
and neutrons have their own magic number, so the
stablest isotopes are those with both proton and
neutron magic numbers. They are "doubly" magic.

Lead-208 is doubly magic nucleus and the heaviest
stable isotope. By "stable," we mean it's eternal. The
next isotope up in weight, Bismuth 209, was long
thought to be stable but it turns out to have a half-life of
19,000,000,000,000,000,000 years, longer than the
age of universe.

"One possible magic number of neutrons for spherical
nuclei is 184, and some possible matching proton
numbers are 114, 120 and 126 - which would mean
that the most stable spherical isotopes would be
ununquadium-298, unbinilium-304 and unbihexium-310.
Of particular note is Ubh-310, which would be doubly
magic (both its proton number of 126 and neutron
number of 184 are thought to be magic) and thus the
most likely to have a very long half-life."
http://en.wikipedia.org/wiki/Island_of_stability

One problem with the currently known superheavies is
that they do not have spherical nuclei. I think they're
distorted by having too few neutrons. That's the real
problem with making superheavies -- not enough
neutrons. Why is it so hard to get a neutron when
you need one?

Unbihexium-310 needs only 126 protons, but it needs
58 more neutrons than protons -- 184 neutrons. You
ever try to get 184 neutrons into one very small room
and make'em settle down and not run around? Imagine
184 two-year-olds in your living room. That's nothing
compared to quieting down 184 neutrons.

The real question here is this -- has anyone ever
searched an entire meteorite for one or two individual
atoms with a weight above 280? Run an entire meteorite
through a mass spectrometer?

The answer is NO. It would be far more ardous than the
huge effort of the German team that ran Pacific sediment
through a mass spectroscope to find supernova iron, Fe60:

<quote>
Interstellar matter formed in a supernova has been discovered on
Earth now for the first time. Light coming to Earth from distant
supernovas is recorded all the time. Likewise, a dozen or so
neutrinos from nearby Supernova 1987A have been detected. But
atoms from supernovas are a different matter. In a sense, all the
heavy atoms on Earth have been processed through or created in
supernovas long ago and far away. But now comes evidence of
atoms from a supernova that may have been deposited here only a
few million years ago. An interdisciplinary team of German
scientists from the Technical University of Munich (Gunther
Korschinek, 011-49-89-289-14257, korschin at physik.tu-
muenchen.de), the Max-Planck Institute (Garching), and the
University of Kiel have identified radioactive iron-60 atoms in an
ocean sediment layer from a seafloor site in the South Pacific.
First, several sediment layers were dated, and only then were
samples scrutinized with accelerator mass spectroscopy, needed to
spot the faintly-present iron. The half-life of Fe-60 (only 1.5
million years), the levels detected in the sample, and the lack of
terrestrial sources point to a relatively nearby and recent supernova
as the origin. How recent? Several million years. How close? An
estimated 90-180 light years. If the supernova had been any closer
than this, it might have had an impact on Earth's climate. The
researchers believe traces of the Fe-60 layer (like the iridium layer
that signaled the coming of a dinosaur-killing meteor 65 million
years ago) should be found worldwide but have not yet been able
to search for it. (K. Knie et al., Physical Review Letters, 5 July
1999.)
<unquote>

IF naturally occuring super-heavy isotopes existed and
IF they were stable or long-lived, meteorites would be
the perfect place to look for them, IF it were technically
feasible.

But is it?


Sterling K. Webb
------------------------------------------------------------------------------------------
----- Original Message -----
From: "Galactic Stone & Ironworks" <meteoritemike at gmail.com>
To: "G?ran Axelsson" <axelsson at acc.umu.se>
Cc: "Meteorite List" <meteorite-list at meteoritecentral.com>
Sent: Monday, July 12, 2010 11:12 AM
Subject: Re: [meteorite-list] Super-heavy elements in meteorites?


Hi Goran and List,

What about the isotopes that reside within the "island of stability"?
Have any traces of them ever been detected? Those isotopes have
longer half-lives.

Best regards,

MikeG


On 7/12/10, G?ran Axelsson <axelsson at acc.umu.se> wrote:
> All the transuranium elements are highly unstable so any trace amounts
> of the super heavy elements are gone in just seconds to days. I think
> it
> is a safe bet that there are none ever detected in meteorites.
> Plutonium (Pu 94) and neptunium (Np 93) are the only transuranium
> elements that have half life measured in years and they are formed by
> decay of uranium, but I've never heard about them being detected in
> meteorites.
>
> /G?ran
>
> Galactic Stone & Ironworks wrote:
>> Hi List!
>>
>> Does anyone know if super-heavy elements are found in meteorites
>> (even
>> in tiny amounts)?
>>
>> Specifically, elements 112 to 119 or the transitionary metals between
>> 104 and 111?
>>
>> Best regards,
>>
>> MikeG
>>
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-- 
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Received on Mon 12 Jul 2010 05:31:53 PM PDT