[meteorite-list] Pluto's Fate to be Decided by 'Scientific andSimp le' Planet Definition

From: Steve Schoner <schoner_at_meteoritecentral.com>
Date: Tue Aug 15 12:27:55 2006
Message-ID: <20060815.091443.713.468969_at_webmail13.nyc.untd.com>

Bigger than Pluto? At greater AUs'out?

This could explain the comets that come out of the blue appear once and
never return.

Did not astronomers think that it was interstellar perturbations that
"jarred" the K-belt?

A large "planet(s)" out there would have much more effect than stars
light years away.

Steve Schoner
IMCA #4470


Re: [meteorite-list] Pluto's Fate to be Decided by 'Scientific
andSimple' Planet Definition

Sterling K. Webb
Tue, 15 Aug 2006 00:05:13 -0700

Hi, All,

   Pluto has infrastructure going for it: 75 years
of textbooks and references to it as planet, down the
mnemonic they use in grade school:
   My Very Educated Mother Just Served Us Nine
Pizzas... for Mercury, Mars, Venus, Earth...

   I think the idea of the "Dwarf Planet" moniker is a mistake.
The three classes of planet proposed. Terrestrial, Gas Giant,
and Dwarf seems sensible at first, but it has flaws. Small
Rocky Worlds is a valid class. Gaseous Giants is OK (but
Neptune may be a small super-terrestrial with a whopping
big atmosphere, but why quibble...?).

   What happens to the category of "dwarf planet" when
and if we discover a TNO bigger than Mercury at 100 AU?
Or a TNO bigger than Mars at 150 AU? Why would I
think that would happen?

   Well, I've been reading everything I could get my hands on
about the planets for fifty years. When I started, the books
said that Pluto was probably 10,000 to 15,000 miles across,
then all of sudden, the newer ones reported sadly that Pluto
was only 6500 miles across, then 3700 miles, then 2500, then
maybe less than 1500, and hey! it wasn't really a planet, just an
escaped moon of Neptune, and that was the end of the solar
system, nobody home all the way out to Oortville.
   Then, Pluto got itself a moon, a big one, and it was a planet
again. But that was it -- nothing else. Then, OK, there are a
few things out there beyond Pluto, but nothing big and not
very many of those.
   Then, OK some of those things are as big as the bigger
asteroids, but they're just freaks. Heck, some of them may have
wandered in and been captured by our solar system. Basically,
the outer system is empty...
   Then, OK, there's thousands of things out there, but they're all
small, insignificant iceballs, like 25-50 km; don't worry. Well,
OK, one of these new asteroidal things out there past Pluto seems
to be bigger than Pluto and, oh, there's a few more of those
bigger things, too. And, my God! they've got moons; maybe
they're planets. And then, Pluto's got THREE moons, and one
of the newbies has got two...
   And just this month, an occultation experiment demonstrated
that the K-Belt has got lots of medium 100-200 km objects, quite
a few in fact... Well, how many? Er, about a quadrillion. (Yeah,
that's what they said, a quadrillion.) I'm not even sure how many
is a quadrillion, 10^15? It's a lot, I know that.

   Do you see a trend here, in fifty years of data?

   This is clearly detection-driven discovery. With every
improvement in our ability to detect, we find more, for 30
years now. Before you assume that you would always find
more, not so. One of the reasons for improving detection
is to reach completeness: you improve and you don't find
anything new; you finally got it all. But so far, the Outer
System just gets busier and busier.

   One of the clues is that 2003UB313 and 2005EL61 and
so forth are not that much further away than Pluto, within

10-12 AU. The detections are using parallax displacement -- watch it
for three weeks and see if it moves relative to the

background sky. But objects further away move more slowly;
you have to watch them longer to detect their movement.
At this point, the searches can't afford to spend that much
time on every patch of sky, so they haven't found any bigger,
further objects... yet.

   It can't go on forever, true. No Black Dwarf star at 500 AU.
But I give it a 50-50 chance that before 2020 we will discover a
TBO bigger than Mercury or even Mars. (I hope sooner; I
hate waiting.)

   What do you do when you discover a Dwarf Planet
BIGGER than a Regular Planet? You can only spend just
so much time in committee rooms... By choosing "dwarf"
as a designation you assume facts not (yet) in evidence.

   Why not just Terrestrial, Gas Giant, and Plutonian Planets?
The 11 year old that suggested the name "Pluto" for the new
1930 Planet did so because he was the Greek god of the nether
regions, so "Plutonian" can be taken to mean "Outer System"
planets (assuming it's big enough to be round and orbits the
Sun).

   Even if Ceres gets an upgrade, it would still work, as
Ceres seems like to be "Plutonian" in composition... I have
a soft spot for Ceres.


Sterling K. Webb
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----- Original Message ----- From: "Ron Baalke" <[EMAIL PROTECTED]>

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Sent: Monday, August 14, 2006 6:57 PM

Subject: [meteorite-list] Pluto's Fate to be Decided by 'Scientific
andSimple' Planet Definition
Received on Tue 15 Aug 2006 12:14:31 PM PDT