[meteorite-list] Re: THE PLANET DEBATE, solar system formation, and meteorites

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Mon Aug 21 10:47:54 2006
Message-ID: <20060821144751.21838.qmail_at_web36912.mail.mud.yahoo.com>

Hi Sterling, all -

This is probably lost on many here, but it appears to
me that the question before the meteorite community is
"Was McSween's formation model right?". Or was the
formation of the asteroids, the source for many
meteorites, related to the LPBE? As many ask, Did the
planets shift after the LPBE?

That may explain the fascination of some here with the
current debate over the definition of planet.

good hunting,
Ed

--- "Sterling K. Webb" <sterling_k_webb_at_sbcglobal.net>
wrote:

> Hi, All,
>
>
> A nice piece written under the title "Is Pluto A
> Giant Comet?"
> contains a wealth of information about the history
> of naming planets:
> http://cfa-www.harvard.edu/cfa/ps/icq/ICQPluto.html
>
> It's a "Dump Pluto" piece, of course, but with
> lots of information
> about how much the naming of planets has changed
> through time.
>
> A few quotes:
> "Astronomy publications and textbooks for nearly
>
> half a century referred to "eleven primary planets"
> of
> the solar system [e.g., P. A. Hansen (1837), in
> Jahrbuch
> fuer 1837, ed. by H. C. Schumacher (Stuttgart and
> Tuebingen: J. G. Cotta'schen Buchhandlung), p. 83;
> D. Olmsted (1847), An Introduction to Astronomy;
> Designed as a Text Book for the Students of Yale
> College
> (New York: Collins and Brother), p. 174; J. H.
> Wilkins (1833),
> Elements of Astronomy (Boston: Hilliard, Gray,
> Little,
> and Wilkins), p. 4], until a rush of asteroid
> discoveries
> in the late 1840s and 1850s encouraged astronomers
> to
> refer to them as "minor planets" or "asteroids"
> instead
> of "primary planets". Olmsted had the four newest
> planets
> as numbers 5, 6, 7, and 8, and Jupiter was the ninth
> planet.
> (Note that the other seven primary planets were
> Mercury-Uranus,
> until Neptune was discovered in 1846.) The eminent
> British
> astronomer Sir John Herschel wrote a series of
> famous
> textbooks on astronomy in the first half of the 19th
> century;
> he, too, counted 11 planets, with Jupiter as the
> ninth, and
> referred to Ceres, Juno, Pallas, and Vesta as
> "ultra-zodiacal
> planets" in his 1833 edition of A Treatise on
> Astronomy."
>
> For a half century, we had 11+ planets, then for
> a half
> century we had 8 planets; for the last half century
> we've
> had 9 planets. The conservatives want to stick with
> nine;
> the ultra-conservatives want to go back to eight.
> Does
> anybody want to move on?
>
> Another good internet reference is David
> Jewett's site
> on the Kuiper Belt Objects:
> http://www.ifa.hawaii.edu/faculty/jewitt/kb.html
>
> From it, I discovered that Julio Fernandez of
> Uruguay,
> the prime mover of the Alternative Definition that
> supports
> the Eight Planet Gang, is the author and sponsor of
> many
> theories of planetary movement (planets changing
> orbits),
> which theories have gotten a big boost from the
> discovery
> of extrasolar planets that apparently have "spiraled
> in"
> toward their stars, but also a big supporter of a
> theory that
> says Neptune spiraled out, pushing up planetary
> rubble as
> it went, to form a narrow Kuiper Belt in front of
> its "gravitational
> snowplow." That theory, of course, makes the objects
> IN
> the Kuiper Belt just trash. Leftovers.
> Three guesses why he'd want to keep that Kuiper
> Belt
> rabble out of the Planet Class.
> Jewett suggests a 1980 paper by Fernandez should
> be
> considered the origin of the idea of the Kuiper Belt
> rather
> than Kuiper's 1951 paper. "If anything, I would say
> that
> J. Fernandez most nearly deserves the credit for
> predicting
> the Kuiper Belt. His 1980 paper (Monthly Notices of
> the
> Royal Astronomical Society, 192, 481-491) is worth a
>
> careful read." Shall we re-name it the Fernandez
> Belt?
>
> So, Jewett is not a supporter of Proposal V,
> either, but his
> website is very well organized, well-written, and
> informative,
> and manages to present things in a sharp clear way,
> and I'm
> enjoying every page of it. He does the best job of
> explaining
> the varieties of KBO's that I've seen to date. He is
> also pretty
> forthright about the problems with all the existing
> theories
> about the Kuiper Belt. For example, Fernandez'
> theory would
> predict a close, sharp outer boundary to the Kuiper
> Belt, but from
> Jewitt we learn that the old boundary at 42 AU had
> to be moved,
> first to 47 AU, then to 53 AU, and now to 100 AU.
> And it's still
> moving...
>
> He has a section under the tab "Plan View" which
> shows
> the KB objects as viewed from above the solar
> system. A good
> picture is worth, well, more than a thousand words.
> I have no
> trouble seeing where those extra-big "planets" I
> expect to be
> found would fit in... I look at the three
> populations: plutinos,
> main belt, and scattered disk, and the first thought
> that popped
> into my head was "Why would you assume the scattered
> disk
> was "scattered" from the K-Belt? It looks to me like
> the inner edge
> of another (inclined) disk of "objects" we are just
> starting to
> discover..." The first glimpses of an Outer Outer
> Solar System.
> Or maybe we should name them (when the time
> comes) the
> Inner (Mercury to Ceres), the Middle (Jupiter to
> Pluto), and the
> Outer System.
> The disheartening thing about eccentric distant
> objects is that
> most of the time they would be too far away to be
> easily detected.
> The enheartening thing about eccentric distant
> objects is that they
> are most likely scattered by a more distant massive
> object. Oh, yes,
> I know that the current theory is that Neptune
> pumped them up and
> out. Piffle! Very hard to do and then only in
> special circumstances.
> But external orbital perturbation over the long term
> is of a much
> higher order of likelihood, impossible to avoid in
> fact. The mere
> presence of a disk of entirely composed of eccentric
> bodies is
> very suggestive.
>
> Indicating that theorists are uneasy about this
> is the sudden rash
> of theories that this or that scattered disk object
> was captured
> from another star. You know, if you had suggested
> stellar capture
> as a mechanism for almost anything for the last
> century, you would
> have been laughed out of town, but now that there an
> inconvenient
> population of objects, suddenly it's "doesn't count;
> it's from
> another star"?
>
> What comes through loud and clear is that we are
> gaining a lot of
> new data at a great rate over the last 10 years and
> trying to wedge
> the new data into earlier theories that were
> formulated on much
> less data than we have now. We need a breather. It
> may be far too
> early to have gotten it right.
>
> The recent Stardust mission shows that comets,
> assumed to have
> formed out in the back end of Kuiper Kountry, are
> chok-full of rich
> high temperature silicate goodness which has to have
> come from
> somewhere very near the Sun. So now we have to make
> a major
> constituent of KBO's from stuff we have to transport
> from very
> close to the Sun out to the back end of the solar
> system in time
> for it to be used in manufacturing comets and other
> icy bodies.
> Doesn't seem like a reasonable explanation to
> me, but then I
> never thought icy bodies formed out there. The
> logical place to
> make lots of icy bodies is at that point in the
> solar system, somewhere
> under 5 AU where H2O vapor at near zero pressure
> condenses
> directly into ice, at about 160-165 deg Absolute. It
> HAS to
> condense; it's got no choice. Now, how do we
> transport the
> tiny grains out to 40 AU to slowly accrete into
> KBO's? We
> make comets there; Jupiter tosses'em out?
>
> Would that explain the brand new occultation
> results that show a
> quadrillion 100-200 km bodies in the K-Belt? A
> quadrillion medium
> sized bodies takes a heap of 'splaining...
>
> Enough for now.
>
>
> Sterling K. Webb
>
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Received on Mon 21 Aug 2006 10:47:51 AM PDT