[meteorite-list] Astronomers to Decide What Makes a Planet

From: Dawn & Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Wed Aug 3 21:09:51 2005
Message-ID: <036701c59891$2b991620$6502a8c0_at_GerryLaptop>

"Gee, I guess there's only ONE planet....." yipee I made it to the right
one, whissu! that was close.
----- Original Message -----
From: "Sterling K. Webb" <kelly_at_bhil.com>
To: "Ron Baalke" <baalke_at_zagami.jpl.nasa.gov>; "Meteorite List"
<meteorite-list_at_meteoritecentral.com>; "Darren Garrison"
<cynapse_at_charter.net>; <MexicoDoug@aol.com>
Sent: Wednesday, August 03, 2005 2:42 PM
Subject: Re: [meteorite-list] Astronomers to Decide What Makes a Planet


> Hi, Ron,
>
> You'll notice that I put quotes around the word "rules."
>
> Yes, there is no formal definition for a planet. There never has been,
only a
> working understanding of what was meant.
>
> There were differences; it has been a topic of discussion. But, there
are
> "working rules," by which I mean that one knows what others in the field
think and
> why.
>
> The consensus compromise was on Pluto. Yes, it was a planet, but it
was too
> small (debatable) and we don't like it. Among other things, because it
didn't fit
> with the other "planets" in the scheme of things, compositionally unique.
>
> Well, there are enough big KBO's to establish a new class in the
scheme of
> things now, obviously. The refuge for those who didn't like Pluto was that
KBO's
> are all small, iceballs, giant comets, etc., hence not essentially
"planet-like."
>
> The compromise rested on the truth of the "small" notion. 2003UB313
blows the
> compromise out of the water. By the given reasoning of those who deny the
> "planethood" of KBO's, 2003UB313 qualifies as a planet. What if 2003UB313
turns out
> to be bigger than Mercury? How do you disqualify it?
>
> Darren thinks KBO's have too many volatiles to be a "planet." What do
you do
> with Saturn; toss it out too? Ok, Saturn's out, along with the rest of the
Jovians.
> MexicoDoug thinks Jupiter is "too big" to be a "planet;" it's a failed
brown dwarf.
> Ok, Jupiter's out. Whoops, already was!
>
> By my count, we now have four planets left. No, Mercury's too small. I
forget
> it was out. Make that three. Well, Venus is too hot and Mars is too cold.
Gee, I
> guess there's only ONE planet after all: Earth, the Center of the
Universe, Home
> Sweet Home.
>
> Haven't we been here before, about 500 years ago?
>
> Truth: there is a population of hundreds or thousands of bodies, some
planet
> sized, in a zone or region of the solar system. They are consistently
composed of a
> comparably even mixture of felsic (and possibly mafic) minerals and
abundant
> cyrogenic minerals. They possess a complex inner dynamic, are known to be
capable
> of vulcanism and likely to additionally possess a wide variety of known
and unknown
> geologic processes.
>
> Sounds like planets to me, not just one planet but PLANETS, in the
decidedly
> plural. The Universe is not getting smaller. Really, it isn't.
>
> "It is not a game, it is just a classification." Truth is the ultimate
game.
> People fight over it. "Classification" is just what you call a thing, and
in
> science you call it what it IS, so it matters more than anything else. The
name
> determines what you think of it as, how you conceive it. The word stands
for the
> nature of the thing's reality.
>
> The unending arguments that consume quantum theory, for example, are
because
> every conceptual identification, or "name," is about the reality of
REALITY. It
> matters, believe me. The arguments ARE quantum theory. This case of
"planets" is
> not as pure an example, but it is important.
>
> The reference to classificatory disputes in meteorites is misleading
because
> for a century meteorites taught us more about the universe than you could
otherwise
> observe, but currently and for the past few decades, we have learned more
about
> meteorites from our exploration of space than we could have learned from
the rocks
> themselves. Even so, meteorites are invaluable as a "sample return"
mission, of an
> informal sort.
>
> The trailing, rather than leading, role of meteorite studies is that
for all
> those years, no one looked over LAFAYETTE or NAKAHLA and said, "O My God,
this
> sucker's from Mars!" I bet somebody thought it, but was far too cautious
to say it.
> If somebody did, it didn't draw much attention.
>
> You have to have a certain amount of guts. Gene Shoemaker is a good
example:
> guts, and he was right. Luis Alvarez is another. Opponents used to grumble
that he
> already had a Nobel Prize; he could say anything he wanted. Louis Frank
has, and
> John O'Keefe had, the same guts; are/were they right? Most folk have a
totally
> negative answer to that, but the jury of time may partially modify their
opinion,
> or not, as the truth may be.
>
> Brown is engaging in a necessary piece of politics, of advocacy,
that's all. So
> am I in my tiny tiny way, but our hearts are pure :-} You try to influence
> decision-makers BEFORE they make decisions. True for politicians; true for
IAU.
>
> The ONLY reason for disqualifying KBO's from EVER being planets is the
mistaken
> notion that they are "only comets" and can't never be planets no matter
how big
> because of their compositional nature. This is completely irrational. How
can you
> exclude them because they are roughly 50% volatiles when you admit the
Jovians,
> some of which may be ENTIRELY volatiles?
>
> Mr. Spock, help me here on this "logic thing."
>
> Next week's IAU decision is only a momentary thing, always subject to
revision.
> Good old science. In researching KBO's, I found several websites that
defined the
> "outer edge" of the Kuiper Belt at 52 AU, asserting that no more KBO's
would be
> found beyond that distance.
>
> Wonder what they thought when 2003UB313 turned up at 97 AU? Yeah, it
comes in
> to 52 AU. Hold on to that... Maybe they're all eccentric and perihelion in
the
> 50's. So what? Big is big, and a population is a population.
>
> What happens when Brown or somebody finds a really big KBO? Like
bigger than
> Mars at 147 AU and magnitude 20.7? Twenty years ago, no KBO's. Ten years
ago,
> scores of KBO's. Today, hundreds of KBO's. You see a trend there? What if
there's a
> Uranus sized one at 360 AU and magnitude 22?
>
> Remember, the anomalies that led to the discovery of Neptune and Pluto
are not
> fully accounted for. They certainly are not accounted for by Pluto itself,
> unmassive as it is. There are still unaccounted residuals, too small to be
useful.
> Then, there's the Pioneer anomaly...
>
> Time will tell. It always does, if you keep looking.
>
>
> Sterling Webb
> ------------------------------------------------
> Ron Baalke wrote:
>
> > >
> > > Two, 2003UB313 IS a planet under the "rules" that were in effect
at
> > > the time of discovery.
> >
> > There is no formal definition for a planet, and that it the crux of the
> > problem. The IAU will be providing a formal definition soon.
> >
> > >You don't change the rules after the game is over
> > > because you don't like the outcome, not even in Paris (or do you?).
> >
> > It is not a game, it is just a classification, which is being modified
> > to accomodate the latest data. Just look at how meteorites are
classified.
> > We would like to classify each meteorite cleanly into its own subgroup.
> > But we occasionaly run into a meteorite that doesn't fit very well
> > in the current classification scheme, so we temporarily label
> > it as 'anomolous'. We eventually modify the classification to
> > accomodate these anomolous meteorites, usually by creating a new
subgroup, or
> > expanding the definition of an existing subgroup. Same thing with the
planets.
> > We have a few anomolous objects that don't fit very in the current
> > classification, which was poorly defined to begin with. We are going
> > through a process of reclassifcation based on the latest data, which
> > was long overdue.
> >
> > Ron Baalke
> >
> > ______________________________________________
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>
>
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Received on Wed 03 Aug 2005 09:09:30 PM PDT