[meteorite-list] OT: HOW MANY PLANETS?

From: Dawn & Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Thu Aug 4 20:01:23 2005
Message-ID: <04af01c59950$c8451090$6502a8c0_at_GerryLaptop>

As always, simplifying a tangled web. Informative AND entertaining. I'm glad
I'm not the only audience enthralled by this interchange between yourself,
Darren, Doug et al.
Thanks to all. The Meteorite List LIVES!!! It is a living entity breaching
the ceiling of the heavens, gulping the ether and beching organic plasma. It
incites thought, passion and a zest for living. It helps remind one of the
wonderous fabric woven so adroitly still beyond our complete understanding.
But we strive, we strive, we strive. What exciting times!!!!!!!
Space Exploration and Earth based Astronomy take us to new heights making
our star rocks ever more precious to each of us!
----- Original Message -----
From: "Sterling K. Webb" <kelly_at_bhil.com>
To: <cynapse_at_charter.net>; <MexicoDoug@aol.com>;
<meteorite-list_at_meteoritecentral.com>
Sent: Thursday, August 04, 2005 6:53 PM
Subject: Re: [meteorite-list] OT: HOW MANY PLANETS?


> Hi, Darren, Doug,
>
> OK, I didn't "do the math," and you can forget that, as it's a complex
simulation that's required;
> the number of factors is staggering. I did do the "research," though,
reading a few (hundred) pages on
> the theoretical models of icy rocky and gassy only bodies.
>
> First, the existence of sub-Jovian, Jovian, and super-Jovian bodies in
close orbits at high
> temperatures around other stars convinces me that a "hot gas giant" is a
possibility, since they
> obviously exist!
>
> John S. Lewis, who developed many of the early theoretical models of
structure for such bodies
> back in the when, wrote a book on the new extra-solar worlds, "Worlds
Without End," and he discusses
> the "hot" giants. These's no theoretical problem; they're "keepers."
>
> Second, it is really difficult to "boil away" a planet like Darren
first suggested in his orbit
> swapping example. Even a Plutonian sized body would merely evolve over
many millions of years, not
> evaporate.
>
> Third, these Plutonians I have been talking about are not all
volatiles, like so many who dislike
> them suggest, not "giant comets." What I probably didn't make clear
writing about them is that they
> are made from "primordial" planetesimals, the equivalent of condensing
them directly from the solar
> nebula without any extensive thermal modification. In other words, they
accreted out where the nebula
> was cool, about 160 K and below.
>
> The solar nebula is, er, was 60% volatiles and 40% rock. The rock has
already formed out at 160 K.
> as grains, dust, pebbles, chunks, etc. In low vapor pressure space, the
water (and uranium oxides,
> oddly enough) condense and accumulate at 160's K. There is some
accretional heating and about 20% of
> the volatiles were driven off as the bodies formed. The resulting planets
are therefore about 50%/50%
> volatiles and rock. This is easy to determine when you can get a density
for these bodies where
> possible and probably applies equally well to all or most of them.
>
> The larger Plutonian bodies are certain to differentiate, leaving a
rocky core and a "volatiles"
> crust and mantle. The use of the word "volatiles" is very mis-leading
here. At these temperatures and
> pressures, they should be regarded as "cryogenic minerals," with a
substantial fraction of the
> strength of the silicate minerals of rock.
>
> A Plutonian body like 2003UB313 will achieve central pressures of
100,000 bar, or 1,500,000
> lb/in^2. Ices have crystal structures that collapse nicely into each other
at far lesser pressures and
> produce a resultant crystal that is very strong, rigid, tightly bonded,
nearly metallic in some cases.
> Their phase diagrams are highly complex, not as simple as a mere rock's.
(I sneer at petrologists
> here.) The interaction of the variety of these volatiles is even more
complex.
>
> The eutectic melting of ammonia and water mixtures will drive you
crazy if you study it long
> enough, believe me. In other words, there is kind of weather possible on a
Plutonian body as close in
> Jupiter's orbit, and obviously Titan is a place where you need an umbrella
AND a warm coat and are
> encouraged not to jump in the methane puddles (too cool for ammonia/water
weather).
>
> The Jovian moons are the model of what a Plutonian world would be
like. Pluto is just Ganymede
> (bigger than Mercury) cooled down to 109 K. Next is a really obvious point
seems to elude a lot of
> heavy thinkers. Jupiter and the other gas giants did not capture every
Plutonian world; some, probably
> most, escaped, ejected into the outer system. Now, which ones got away:
the little ones or the big
> ones? Doh.
>
> Yes, even the biggest gravitational fisherman of all, Jupiter, had
"the big one(s) that got away"!
> That's BIGGER than Ganymede, Europa, Callisto, Io. Maybe the Jovian
satellites formed in place; maybe
> not. I say not. All the other gas giant moons look like captures -- them
too, sez I. This is not say
> that the Plutonian bodies accreted at 5 AU, only that that's the minimum
distance. They could (and
> presumably did) accrete anywhere out from there, although exactly where is
a mystery for a while.
>
> This why one could be (and still can be) confident of finding large
outer system bodies like
> 2003UB313 and its undiscovered and still larger companion planets. I said
"planets," IAU. It should
> not have been a surprise! It probably was not to the successful searchers,
but a certain number of
> minds seem to be struggling with reality here.
>
> Hey, wait, you say, Jupiter's moon IO is not "Plutonian"! Ah, but it
is. You take a 50/50 ice/rock
> Plutonian body, tidally heat it for billions of years, drive off the water
and other volatiles slowly.
> The hot water reacts with the abundant sulfides in the solar mix which are
converted to sulfur and
> sulfur oxides, too heavy to escape. You are left with the rocky core (80%
of the original diameter)
> covered with bubbling sulfur circuses!
>
> THIS is the answer to Darren's original question: what would happen if
you took Pluto or 2003UB313
> and put them in Mercury's orbit or Venus' orbit. Darren, you have
accidentally discovered the secret
> formula for making an IO!! You've just stumbled on to the KFC "original
recipe," or forced the dog to
> spill the bean recipe!
>
> As for hot gas giants, Uranus or Neptune could retain a lot for a lot
longer; their high densities
> suggest a substantial rocky core. Jupiter's core is problematical and
small if there is one, but its
> gravity is working just fine, thank you. Saturn, at a density of 0.68, is
probably all-volatiles but
> that makes no difference.
>
> However, though life would change some on a hot dry gas giant, much
(most) of the gas is retained
> easily. Above 350 C, all water is removed from the atmosphere and surface
and the atmosphere becomes
> transparent, bright and clear, but life goes on anyway without the
previous gloom.
>
> Heat is NOT a problem for gas giants. The planet's oceans of
pressurized fluids (and solids) are
> very hot anyway. Jupiter's core temperature is 20,000 C or more!! Only the
very outer layers of a gas
> giant are cool, a thin cooled skin or scum formed over the inferno raging
beneath, which radiates away
> more heat from the planet in Jupiter, for example, than Jupiter receives
from the Sun. If you think
> Venus is Hell, try again.
>
> The "cool and distant" gas giants of our mind's eye are in fact the
hottest worlds in the solar
> system already. The interiors of a Plutonian world are probably similar to
the core temperatures of a
> comparably sized Terrestrial world, possibly even hotter, as there are
indications that more
> radioactive isotopes would be present, persist longer, and contribute more
to heating than in a
> Terrestrial world.
>
>
>
>
> Darren Garrison wrote:
>
> > On Wed, 3 Aug 2005 20:12:01 EDT, MexicoDoug_at_aol.com wrote:
> >
> > >Darren, if we swapped Uranus with Earth something similar to what you
> > >envision might happen to Uranus at 1 AU as well...though your point is
a good one
> > >to mull over...
> >
> > I haven't done the math on it (and to be honest, would have to do a bit
of brushing up before I
> > COULD do the math) but I was thinking that the Jovans had enough gravity
to hold their atmospheres
> > even at 1 AU temperatures. Think about all of those "hot Jupiters"
discovered over the past few
> > years. Anyone know the mass limit for a Jovan to keep it's volitiles?
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Received on Thu 04 Aug 2005 08:01:07 PM PDT