Soon 12 planets in the solar system !

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Date: 16 Aug 2006 12:20:22
From:
Subject: Soon 12 planets in the solar system !

Hi,

Soon there will be probably 12 planets in the solar system !
ercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto,
Charon and 2003 UB313
See the latest IAU news at :
http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html

It is amazing that knowing that the definition states that "A planet is a
celestial body that (a) has sufficient mass for its self-gravity to overcome
rigid body forces so that it assumes a hydrostatic equilibrium (nearly
round) shape, and (b) is in orbit around a star, and is neither a star nor a
satellite of a planet." that IAU committee has considered Charon as a true
planet... Isn't it the satellite of a planet itself orbiting the Sun ?
And the Moon is this case ? In-betwene lines, IAU's definition means that a
body has to show a mass over about 5x10^20 kg, and show a diameter > 800 km
or so. The Moon is round, and close to 3400 km in diameter... !

I wonder what does Michael Brown (who is not member of IAU) think of this
idea paradox (I image his answer, it is not more a question for astronomers
but only administrative).

Anyway, in all cases that will be always the status quo for amateurs... ;-)

Have a clear and dark sky (as far as possible;..)

Thierry
http://www.astrosurf.org/lombry

Date: 16 Aug 2006 09:54:30
From: Rich
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:
> Rich,
>
> Say you discovered Pluto and what would you think after 76 years that
> it was going to be demoted?
>
> I don't think you would like it either.

Maybe not, but it would have nothing to do with science and everything
to do with
emotion.

>
> Personally, I thought just saying Pluto is the lower limit might have
> been fine.
> To demote it to me at least is like saying that Websters dictionary ...
>
> Waits a full 76 years until it includes a new word and it's definition
> which would make
> Astronomers look pretty ridiculous.

There is more to Pluto being "odd" than it's size. It's shape and its
orbit come to mind.

Date: 17 Aug 2006 13:46:07
From: Alan French
Subject: Re: Soon 12 planets in the solar system !

"Rich" <rander3127@gmail.com > wrote in message
news:1155747270.498224.81570@i3g2000cwc.googlegroups.com...
> There is more to Pluto being "odd" than it's size. It's shape and its
> orbit come to mind.

As far as I can find, it is essentially round.

Clear skies, Alan

Date: 17 Aug 2006 08:28:21
From: Brian Tung
Subject: Re: Soon 12 planets in the solar system !

Alan French wrote:
> As far as I can find, it is essentially round.

Rich has had a long-standing contention that Pluto is significantly out
of round. I'm not sure what he's using as his basis for that, though.

--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

Date: 16 Aug 2006 10:16:22
From: Davoud
Subject: Re: Soon 12 planets in the solar system !

Thierry wrote:

> Soon there will be probably 12 planets in the solar system !
> ercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto,
> Charon and 2003 UB313
> See the latest IAU news at :
> http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html

> It is amazing that knowing that the definition states that "A planet is a
> celestial body that (a) has sufficient mass for its self-gravity to overcome
> rigid body forces so that it assumes a hydrostatic equilibrium
> (nearly round) shape, and (b) is in orbit around a star, and is neither
> a star nor a satellite of a planet." that IAU committee has considered
> Charon as a true planet... Isn't it the satellite of a planet itself
> orbiting the Sun ?

> ...

...vanity of vanities; all is vanity.

In re: Charon, you missed that part of the definition in footnote 2
that reads "For two or more objects comprising a multiple object
system, the primary object is designated a planet if it independently
satisfies the conditions above. A secondary object satisfying these
conditions is also designated a planet if the system barycentre resides
outside the primary. Secondary objects not satisfying these criteria
are 'satellites'. Under this definition, Pluto's companion Charon is a
planet, making Pluto-Charon a double planet."

"Rich" said "Lets hope nostalgia over Pluto and it's discoverer does
not have any effect on a decision."

I say "Lets hope that an irrational desire to demote Pluto does not
have any effect on a decision."

Why are people so hung up on the need to demote Pluto? Is it
/necessary/ to demean Tombaugh's achievement?

The definition as quoted works. Adopt it and move on.

Davoud

--
usenet *at* davidillig dawt com

Date: 17 Aug 2006 20:58:44
From: CNJ999
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:
> I just believe that after 76 years to demote Pluto is like saying that
> it
> should take Websters 76 years to agree that a new word is real word and
> as such, attains a space in the dictionary along with it's definition.
>
> Although I didn't talk to Clyde when he was here at The Franklin
> Institute in Philly
> some years ago, there are a few of my friends and aquaintances who knew
> him.
>
> I just feel that if someone makes a big discovery that it is most
> unkind to
> "steal" it away after his or her death.

The simple fact of the matter is that Clyde discovered the brightest of
the KBO, not a new planet in the sense of the other 8. As has been
noted various places, the first four asteroids discovered were
initially called "planets" for a very long time, until it was realized
that the solar system was filled with these tiny rocky bodies. There
didn't seem to be any harm done to anyone when the "big 4" were righty
reclassified as simply as asteroids. What is the big deal about
properly classifying an object in terms of what it is? I agree with
Gregg, this is about playing politics, not science at work...and a
disgrace to boot!

JBortle

Date: 17 Aug 2006 23:07:45
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

CNJ999 wrote:
> Ed wrote:
>> I just believe that after 76 years to demote Pluto is like saying that
>> it
>> should take Websters 76 years to agree that a new word is real word and
>> as such, attains a space in the dictionary along with it's definition.
>>
>> Although I didn't talk to Clyde when he was here at The Franklin
>> Institute in Philly
>> some years ago, there are a few of my friends and aquaintances who knew
>> him.
>>
>> I just feel that if someone makes a big discovery that it is most
>> unkind to
>> "steal" it away after his or her death.
>
> The simple fact of the matter is that Clyde discovered the brightest of
> the KBO, not a new planet in the sense of the other 8. As has been
> noted various places, the first four asteroids discovered were
> initially called "planets" for a very long time, until it was realized
> that the solar system was filled with these tiny rocky bodies. There
> didn't seem to be any harm done to anyone when the "big 4" were righty
> reclassified as simply as asteroids. What is the big deal about
> properly classifying an object in terms of what it is? I agree with
> Gregg, this is about playing politics, not science at work...and a
> disgrace to boot!

I think you and Crinklaw are asses, but then again, you're amateurs.

So I guess the pros will just have to cut you some slack.

You need to become gravitationally relaxed.

http://cosmic.lifeform.org

Date: 17 Aug 2006 13:48:12
From: Ed
Subject: Re: Soon 12 planets in the solar system !

I just believe that after 76 years to demote Pluto is like saying that
it
should take Websters 76 years to agree that a new word is real word and
as such, attains a space in the dictionary along with it's definition.

Although I didn't talk to Clyde when he was here at The Franklin
Institute in Philly
some years ago, there are a few of my friends and aquaintances who knew
him.

I just feel that if someone makes a big discovery that it is most
unkind to
"steal" it away after his or her death.

Date: 18 Aug 2006 07:34:30
From: Ed
Subject: Re: Soon 12 planets in the solar system !

Thomas Lee Elifritz

We are being a bit pretentious these days are we not?
Methinks you are a rank amateur.

Better get out your telescope and get some star time down buddy
to help you clear your head and then get some good shuteye followed
by a healthy dose of sunlight.

Maybe the combination will help with what ails you my boy.

Date: 18 Aug 2006 09:44:32
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:

> We are being a bit pretentious these days are we not?
> Methinks you are a rank amateur.

That'll get us out to Ceres.

> Better get out your telescope and get some star time down buddy
> to help you clear your head and then get some good shuteye followed
> by a healthy dose of sunlight.

Ceres needs an orbiter and a lander you amateur.

> Maybe the combination will help with what ails you my boy.

NASA and the US government ails me.

Impeachment is the only cure for us now.

http://cosmic.lifeform.org

Date: 18 Aug 2006 05:36:00
From: CNJ999
Subject: Re: Soon 12 planets in the solar system !

Thomas Lee Elifritz wrote:
> CNJ999 wrote:
> > Ed wrote:
> >> I just believe that after 76 years to demote Pluto is like saying that
> >> it
> >> should take Websters 76 years to agree that a new word is real word and
> >> as such, attains a space in the dictionary along with it's definition.
> >>
> >> Although I didn't talk to Clyde when he was here at The Franklin
> >> Institute in Philly
> >> some years ago, there are a few of my friends and aquaintances who knew
> >> him.
> >>
> >> I just feel that if someone makes a big discovery that it is most
> >> unkind to
> >> "steal" it away after his or her death.
> >
> > The simple fact of the matter is that Clyde discovered the brightest of
> > the KBO, not a new planet in the sense of the other 8. As has been
> > noted various places, the first four asteroids discovered were
> > initially called "planets" for a very long time, until it was realized
> > that the solar system was filled with these tiny rocky bodies. There
> > didn't seem to be any harm done to anyone when the "big 4" were righty
> > reclassified as simply as asteroids. What is the big deal about
> > properly classifying an object in terms of what it is? I agree with
> > Gregg, this is about playing politics, not science at work...and a
> > disgrace to boot!
>
> I think you and Crinklaw are asses, but then again, you're amateurs.
>
> So I guess the pros will just have to cut you some slack.
>
> You need to become gravitationally relaxed.
>

Gregg an I may indeed be amateurs but what pathetic sort of individual
do you represent yourself as?

JBortle

Date: 18 Aug 2006 09:17:29
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

CNJ999 wrote:
> Thomas Lee Elifritz wrote:
>> CNJ999 wrote:
>>> Ed wrote:
>>>> I just believe that after 76 years to demote Pluto is like saying that
>>>> it
>>>> should take Websters 76 years to agree that a new word is real word and
>>>> as such, attains a space in the dictionary along with it's definition.
>>>>
>>>> Although I didn't talk to Clyde when he was here at The Franklin
>>>> Institute in Philly
>>>> some years ago, there are a few of my friends and aquaintances who knew
>>>> him.
>>>>
>>>> I just feel that if someone makes a big discovery that it is most
>>>> unkind to
>>>> "steal" it away after his or her death.
>>> The simple fact of the matter is that Clyde discovered the brightest of
>>> the KBO, not a new planet in the sense of the other 8. As has been
>>> noted various places, the first four asteroids discovered were
>>> initially called "planets" for a very long time, until it was realized
>>> that the solar system was filled with these tiny rocky bodies. There
>>> didn't seem to be any harm done to anyone when the "big 4" were righty
>>> reclassified as simply as asteroids. What is the big deal about
>>> properly classifying an object in terms of what it is? I agree with
>>> Gregg, this is about playing politics, not science at work...and a
>>> disgrace to boot!
>> I think you and Crinklaw are asses, but then again, you're amateurs.
>>
>> So I guess the pros will just have to cut you some slack.
>>
>> You need to become gravitationally relaxed.
>>
>
> Gregg an I may indeed be amateurs but what pathetic sort of individual
> do you represent yourself as?

I represent myself as an individual who thinks that gravitational
relaxation is better then most criterion, for distinguishing big blobs
from little blobs. I'm definitely not a curmudgeon stuck in the past,
nor am I intellectually crippled as you two appear to be.

http://cosmic.lifeform.org

Date: 18 Aug 2006 09:56:37
From: Davoud
Subject: Re: Soon 12 planets in the solar system !

Thomas Lee Elifritz wrote:
> > I think you and Crinklaw are asses, but then again, you're amateurs.

CNJ999
> Gregg an I may indeed be amateurs but what pathetic sort of individual
> do you represent yourself as?

Anyone who thinks that "amateur" -- one who undertakes an activity for
the love of it -- should be used as an insult has a profound
intellectual deficiency. I would cite Albert Einstein, the patent clerk
cum amateur physicist.

Davoud

--
usenet *at* davidillig dawt com

Date: 18 Aug 2006 09:24:01
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Davoud wrote:
> Thomas Lee Elifritz wrote:
>>> I think you and Crinklaw are asses, but then again, you're amateurs.
>
> CNJ999

>> Gregg an I may indeed be amateurs but what pathetic sort of individual
>> do you represent yourself as?
>
> Anyone who thinks that "amateur" -- one who undertakes an activity for
> the love of it -- should be used as an insult has a profound
> intellectual deficiency. I would cite Albert Einstein, the patent clerk
> cum amateur physicist.

Being in love with dictionary definitions is a mark of the rank amateur.

When we encounter an extrasolar system with a bunch of 800 mile diameter
planets, I suppose you will exclaim they can't be planets, because they
aren't like our planets. You really need to diversify your thinking,
otherwise a future in science is going to be devastating for you.

These are excellent criterion they have developed. They should pass with
ease. The only fuzzy part is borderline gravitational relaxation for the
smallest planets, and in those cases, planetoid usually suffices.

Ceres sets a new standard that we all can enjoy, and I think it's a
travesty that NASA has not yet visited, orbited. mapped and studied the
fifth planet from the sun, and that Bush and Griffin canceled DAWN.

http://cosmic.lifeform.org

Date: 18 Aug 2006 14:53:12
From: Ed
Subject: Re: Soon 12 planets in the solar system !

It really doesn't matter...oh, I've heard that line before too:)
It might matter a whole lot since astronomers are always looking for
$$$ to fund their research and pay for their room & board and if folks
get to cranky it might mean less $$$.

So I say to astronomers, keep Pluto and keep your job...or lose Pluto
and see your funding go down a Black Hole.

Date: 18 Aug 2006 10:42:40
From: Ed
Subject: Re: Soon 12 planets in the solar system !

Just take a look at Space.com to get a feel for what folks are
thinking.
You know, I used to take it to heart when folks misunderstood astronomy
as
astrology.

Today, I am also ashamed to be an astronomer as the pros are acting
just as nutty as the Bush administration is.

The world is being run by all the nuts it seems.

Date: 20 Aug 2006 09:19:15
From:
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw ha escrito:

> Hi Chris,
>
> Chris L Peterson wrote:
> > On Thu, 17 Aug 2006 13:17:56 -0600, Greg Crinklaw
> > <theskyhoundyoureye@yahoo.com> wrote:
> >
> >> For once I agree with you John. The more I think about what they are
> >> doing the more ashamed I become of being an astronomer...
> >
> > Geez Greg, what they are doing is unnecessary, and a bit silly, but no
> > reason to be ashamed of being an astronomer! <g>
>
> I'm serious though-- how many real sciences would kludge up a
> classification scheme based on politics and pseudoscience?

It is in fact apalling to see how the IAU is afraid of offending the
(usually dimwitted) public.

>
> > Just do what at least half the astronomical community is going to do:
> > largely ignore the new nomenclature if it's approved.
>
> You betcha. ;-)

Well, something you will have to do. Because what you rationally
*cannot* do, is call Pluto a planet and not call 2003UB313 a planet as
well. It=B4s either both or none.

>
> But seriously, I hadn't really given that much thought. It would put me
> in a pretty difficult position with my software because my users would
> be similarly split. Adding Charon and "Xena" to the observing list of
> planets is just plain stupid...

That=B4s right. So why don=B4t you just limit yourself to what the IAU
wants to call "Classical Planets"? If you want to go for more exotic
stuff, nobody will hinder you.

> Hell, most software doesn't even allow a
> satellite to be a planet too. And the orbits of Ceres and "Xena" are in
> the wrong databases! So I'm supposed to rewrite my code now? Which one
> of these dolts is going to reimburse me for my time on that?
>
> Sheesh!

Computer programs are based on tradition. Otherwise Bill Gates
wouldn=B4t have become so rich (MS-DOS and Windows forever).

In science however, tradition is an impediment.

>
> The goals of this endeavor should be:
>
> (1a) Define a scientific taxonomy
>
> or
>
> (1b) Define a tradition-based taxonomy

1b) is not an option, since it is the product of ignorance. And
deliberate ignorance (that is, deliberately ignoring available data) is
stupidity.

1a) Is what they are working on. So if you have anything *constructive*
to contribute, please do it.

>
> (2) A definition that ends the arguments over what is a planet

You cannot end arguments with rational definitions, if there is so much
irrationality involved as there is in this issue. This is an issue of
reason versus passion, and the passionate monkeys will just have to
understand that their opinion is absolutely worthless.

>
> (3) A definition that is practical and consistent in the real world of
> elementary school classrooms and amateur astronomers

Since when are science standards made by elementary school kids and
science amateurs? Paradigm shifts will always meet with public
resistence if they run counter to social acceptation. But social
acceptation ought to be irrelevant to science.
It is science which has to teach the (naturally stupid, see above
definition of this term) public *how to find out* what is the real
world (and not what it is, since nobody really knows that), and not
vice versa.

>
> (4) A definition that is simple

In its core, the proposal of the IAU is in fact very simple: A planet
is everything massive enough to be reasonably round and which orbits
around a star and is neither a star nor a satellite of a planet by
itself. If that is too complicated for anyone, then that person should
stay out of astronomy (how about doing pottery?).

But we must take into account, that the history of science has
demonstrated that after much investigation the phenomena at hand tend
to turn out being more complex than we initially thought. And this is
what has recently happened to our concept of the solar system. Ignoring
this would be an act of stupidity (see above definition). And this is
the reason of the the fine print in the definition proposed by the IAU.
If things get more complex, so have to become our concepts of them.

The issue of the barycenter of multiple planets was proposed to avoid
possible endless quarrels if we might one day actually find two planets
of (next to) equal mass circling each other. If we simply would say
that the more massive one is the planet and the less massive one is its
sattelite, then we might never be able to figure out which one is
which. The shortcoming in this definition in the case of the barycenter
popping in and out of one of its components if there is a very
eliptical orbit can be easily remedied by demanding that the barycenter
stays out of any of the components at any time for there to be a
multiple planet. As you will see below, it really doesn=B4t matter if
there are 11 or 12 planets in our solar system FOR RIGHT NOW.

And the function of the term "Plutons" is to assure that elementary
school kids will learn that the solar system is much more complex than
it was believed until recently. The terms "Kuyper Belt Objects" or even
"KBO=B4s" will sound rather exotic and hard to memorize for such kids.
So this is why WE HAVE TO GET RID OF THESE TWO TERMS. To me, the term
"Plutons" sounds quite cute and thus apt for this purpose. Today there
are far more people who know about the existence of galaxies, then
there are people who know about the existence of KBO=B4s, even though
the former objects are much further away from home. And this must
change. If you know of a better term suggest it, as long as it serves
the above purpose.

The only politically motivated part of the IAU proposal is just this
distinction between "classical-" and "dwarf planets", the "classical"
ones being visible with the naked eye or minimal optical means
(binocular). But in the end, they are all planets. School kids should
not be obliged to name more than the eight classical ones. Note that
Mercury has a diameter of only 3.4% that of Jupiter, so the range of
diameters among the traditional eight planets is already vast. By
comparison, 2003UB313 has a whooping 50% the diameter of Mercury!!
Besides, according to the IAU proposal up to now there is only one
dwarf planet which is not a Pluton: Ceres (photographically proven to
be round). But I wonder if there exists the posibility that some newly
discovered Centaur might one day turn out to be a planet. Those
unwilling to change their concepts should not only stay out of
astronomy, but stay out of science in general.

As far as the issue of "big" and "small" is concerned: they are not
scientific terms. That=B4s why the distinction between "classical" and
"dwarf planets" is merely a political concession (and not too relevant
- see above).
Our innate hunter/gatherer concept of distance appears to only stretch
over a few days walk. It doesn=B4t take an airplane: Just step into a
car and you will be able to pass through so many landscapes in one
single day that you won=B4t be able to record all of them at the end of
it. So when it comes to "big" and "small" with regard to astronomical
objects, everybody here please just desinflate. Even at a local scale
the universe is far too big for anyone of us to really imagine it.

Since the sphericalness of Mimas, the sixth moon of Saturn, is somewhat
doubtfull, the smallest clearly sperical body we know in the solar
system is Miranda, the 11th moon of Uranus with a diameter of 472 km.
And those who consider a diameter of 472 km to be too small for a
planet might please imagine a sphere with a diameter of 472 km rolling
over the surface of Earth (hopefully not towards them). Half of this
sphere would extend beyond the Troposphere and into the Ionosphere. If
it would roll across Mount Everest you would=B4nt even notice the bump.
At night you would see the flashes of satelites smashing into it and
exploding. The ISS would hit it about in the middle. Now those who
believe that to be "too small" for a planet must suffer from a severe
case of hybris. What really is small are we piffy humans and not
planets.

And please remember that that the actual IAU proposal of 12 planets is
just the beginning. Between Pluto and Charon there are still 2003EL61
and 2005FY9 (and who knows how many more) which might be intermediate
in size. And if, for example, we would assume the typical albedo of a
KBO to be 0.05 and take 472km as the lower cutoff value for a spherical
body, we would end up with about 52 candidates for planethood AS OF
RIGHT NOW (on 8-19-06. On 9-25-05 there were 7 less, according to my
calculations based on data taken from
http://www.ifa.hawaii.edu/faculty/jewitt/kb.html).

In summary, the simplest possible answer to the question of "how many
planets are there in our solar system?" is: "There are lots of planets
in our solar system. We don=B4t know exactly how many there are. We can
only estimate their number. Every year we discover new planets or
candidates for being planets. It=B4s just like with comets". If that
ain=B4t simple, I don=B4t know what is.

>
> This proposal fails on all counts!
>
> I sure hope they wake up.

.=2E...says someone who apparently insists on staying asleep. Above all,
you must remember the following (I repeat, and it seems like that I
have to do it in capital letters):

YOU CANNOT CALL PLUTO A PLANET WITHOUT CALLING 2003UB313 A PLANET AS
WELL. IT=B4S EITHER BOTH OR NONE.

If you know of a better way to deal with this fact than the IAU then
please let us (an above all, the IAU) know.=20

Peter

Date: 20 Aug 2006 10:58:55
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

You are wrong that the current proposal is based on science. It is
simply an ad hoc classification that makes arbitrary divisions. In
reality, using "roughly spherical" as a distinction is no less arbitrary
than using the orbit or mass of Pluto. It has no physical meaning
beyond being something that can be defined.

The real problem with this proposed solution is that it causes trouble.
Real world trouble for lots of people, from educators to planetaria to
software developers. It also exposes the astronomical community to
ridicule. We would forever be arguing about which KBO is a planet (or
not) and adding planets to an ever growing list. People are right to
say, "What? You mean the moon of Pluto is now a planet, but Ganymede
isn't? And I heard the moon would someday be a planet too!" The
laughter about the silly astronomers has already begun!

That's a high price to pay.

I am willing to pay that price. But we need to get something worthwhile
in return for it. A classification scheme based on how the bodies form,
where they form, or what they are primarily composed of, would be a real
science-based model. I would be willing to pay the high price for that.
I am reluctant to pay such a high price for something that amounts to
little more than an arbitrary political compromise!

ph42@infocanarias.com wrote:
>> This proposal fails on all counts!
>>
>> I sure hope they wake up.
>
> .....says someone who apparently insists on staying asleep. Above all,
> you must remember the following (I repeat, and it seems like that I
> have to do it in capital letters):
>
> YOU CANNOT CALL PLUTO A PLANET WITHOUT CALLING 2003UB313 A PLANET AS
> WELL. IT�S EITHER BOTH OR NONE.
>
> If you know of a better way to deal with this fact than the IAU then
> please let us (an above all, the IAU) know.

I have taken the time to make to propose two different solutions that I
feel are better on different threads. I also feel that the alternative
solution under consideration by the IAU is a better choice. Regardless,
claiming that someone who has no better solution somehow gives up their
right to call a bad a solution a bad solution, is specious.

Greg

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 20 Aug 2006 17:31:11
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:

> People are right to say, "What? You mean the moon of Pluto is
> now a planet, but Ganymede isn't? And I heard the moon would
> someday be a planet too!" The laughter about the silly
> astronomers has already begun!
>

While the 70 ft, un-permitted flagpole Donald Trump recently installed
locally has gotten a fair amount of attention and letters to local
newspapers, I've yet to see *one* letter on this topic. The
"laughter" seems very muted amongst non-astronomers.

Phil

Date: 20 Aug 2006 12:12:01
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

Phil Wheeler wrote:
> Greg Crinklaw wrote:
>
>> People are right to say, "What? You mean the moon of Pluto is
>> now a planet, but Ganymede isn't? And I heard the moon would
>> someday be a planet too!" The laughter about the silly
>> astronomers has already begun!
>>
>
> While the 70 ft, un-permitted flagpole Donald Trump recently installed
> locally has gotten a fair amount of attention and letters to local
> newspapers, I've yet to see *one* letter on this topic. The
> "laughter" seems very muted amongst non-astronomers.

What planet do you live on? :-) I mean, are you claiming I'm imagining
things? How absurd.

I've seen many examples of ridicule already, including posts made to
this forum and a link to a cartoon posted just today. SAA is the front
line, so to speak. The comments you see here are an advance view of
what is going to happen in the general public in the coming years if
this proposal is adopted.

What I see in this day on SAA is that the real discussion has ended.
Now the people who were on the periphery are sniping at bits and pieces
of what was said, in rather nonconstructive and unnecessary ways.

In other words, its time for me to get out of the conversation.

Greg

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 20 Aug 2006 18:21:36
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:
> Phil Wheeler wrote:
>> Greg Crinklaw wrote:
>>
>>> People are right to say, "What? You mean the moon of Pluto is
>>> now a planet, but Ganymede isn't? And I heard the moon would
>>> someday be a planet too!" The laughter about the silly
>>> astronomers has already begun!
>>>
>>
>> While the 70 ft, un-permitted flagpole Donald Trump recently installed
>> locally has gotten a fair amount of attention and letters to local
>> newspapers, I've yet to see *one* letter on this topic. The
>> "laughter" seems very muted amongst non-astronomers.
>
> What planet do you live on? :-) I mean, are you claiming I'm imagining
> things? How absurd.
>

Oh, no -- that just wouldn't be possible! ;)

> I've seen many examples of ridicule already, including posts made to
> this forum and a link to a cartoon posted just today. SAA is the front
> line, so to speak. The comments you see here are an advance view of
> what is going to happen in the general public in the coming years if
> this proposal is adopted.
>

A tad arrogant to think that SAA is a leader in
developing opinion among the "general public".
There is no precedent for this view.

> its time for me to get out of the conversation.
>

Good idea, that.

Phil

Date: 22 Aug 2006 13:11:44
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

Phil Wheeler wrote:
>> I've seen many examples of ridicule already, including posts made to
>> this forum and a link to a cartoon posted just today. SAA is the
>> front line, so to speak. The comments you see here are an advance
>> view of what is going to happen in the general public in the coming
>> years if this proposal is adopted.
>
> A tad arrogant to think that SAA is a leader in developing opinion among
> the "general public". There is no precedent for this view.
> its time for me to get out of the conversation.

Arrogant? So anyone who disagrees with you is now arrogant? I think
you need to get a dictionary.

> Good idea, that.

I've always had respect for you, Phil. Until now, that is. This
response of yours is just mean spirited name calling. Like I said, it's
time to get out when people start being assholes instead of listening to
each other and arguing points on their merit. You should have simply
left my original *opinion* be rather than attacking and ridiculing it.
You stepped over that line sir, not me.

So long.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 22 Aug 2006 19:23:18
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:
>
> I've always had respect for you, Phil. Until now, that is. This
> response of yours is just mean spirited name calling. Like I said, it's
> time to get out when people start being assholes instead of listening to
> each other and arguing points on their merit. You should have simply
> left my original *opinion* be rather than attacking and ridiculing it.
> You stepped over that line sir, not me.
>

What name did I call you? Certainly not the one
above, Greg. "Arrogant" was not perhaps the best
choice of words (perhaps "naive" would have been
better).

But my statement was rational, not mudslinging as
you suggest: SAA does not set or lead opinion
among the "general public".

BTW .. I like having 12 planets ;)

Phil

Date: 22 Aug 2006 13:37:17
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

Hi Phil,

Phil Wheeler wrote:
> What name did I call you? Certainly not the one above, Greg.
> "Arrogant" was not perhaps the best choice of words (perhaps "naive"
> would have been better).

Well, I agree then that arrogant was a poor choice of words, because as
far as I understand it, an idea or opinion cannot be arrogant, only a
person... It's a criticism of the person and how they said something
rather than a criticism of a fact or opinion. Not to self: I guess it's
a good idea to remember that not everyone means exactly the same thing
when they say something. I apologize for over-reacting.

> But my statement was rational, not mudslinging as you suggest: SAA does
> not set or lead opinion among the "general public".

Yes, of course. Only, that's not what I meant. I simply meant that the
sort of ridicule we have seen here (particularly from newbies and
neophytes) is naturally the sort of thing we are going to see on a
larger scale. That doesn't mean the whole world cares or will have an
opinion, just that I believe there will be wider ridicule, and that the
ridicule will continue as more and more planets are added (and argued over).

> BTW .. I like having 12 planets ;)

How about 50? ;-)

Mars: sixth planet from the sun... I'd be happy to change the number of
planets if there was a good reason to do so, but the proposal under
review is so arbitrary that I don't see how it could possibly be
justified, considering how many things it'll screw up. Anyhow, that's
my opinion. You are welcome to yours, of course.

Greg

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 22 Aug 2006 20:54:21
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:
> Hi Phil,
>
> Phil Wheeler wrote:
>> What name did I call you? Certainly not the one above, Greg.
>> "Arrogant" was not perhaps the best choice of words (perhaps "naive"
>> would have been better).
>
> Well, I agree then that arrogant was a poor choice of words, because as
> far as I understand it, an idea or opinion cannot be arrogant, only a
> person... It's a criticism of the person and how they said something
> rather than a criticism of a fact or opinion. Not to self: I guess it's
> a good idea to remember that not everyone means exactly the same thing
> when they say something. I apologize for over-reacting.
>
>> But my statement was rational, not mudslinging as you suggest: SAA
>> does not set or lead opinion among the "general public".
>
> Yes, of course. Only, that's not what I meant. I simply meant that the
> sort of ridicule we have seen here (particularly from newbies and
> neophytes) is naturally the sort of thing we are going to see on a
> larger scale. That doesn't mean the whole world cares or will have an
> opinion, just that I believe there will be wider ridicule, and that the
> ridicule will continue as more and more planets are added (and argued
> over).
>
>> BTW .. I like having 12 planets ;)
>
> How about 50? ;-)
>
> Mars: sixth planet from the sun... I'd be happy to change the number of
> planets if there was a good reason to do so, but the proposal under
> review is so arbitrary that I don't see how it could possibly be
> justified, considering how many things it'll screw up. Anyhow, that's
> my opinion. You are welcome to yours, of course.
>

Your points are well taken, Greg.

Things do change, and can change again. I have an
astronomy book of my grandmother's (signed by her
in Hannibal, MO in 1899) which has a planet Vulcan
identified .. invented pre-Einstein to explain
perturbations in Mercury's orbit.

Phil

Date: 22 Aug 2006 15:47:53
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:

>> BTW .. I like having 12 planets ;)
>
> How about 50? ;-)
>
> Mars: sixth planet from the sun...

Complete ignorance of astronomy noted.

http://cosmic.lifeform.org

Date: 22 Aug 2006 19:19:35
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:
> Phil Wheeler wrote:
>>> I've seen many examples of ridicule already, including posts made to
>>> this forum and a link to a cartoon posted just today. SAA is the
>>> front line, so to speak. The comments you see here are an advance
>>> view of what is going to happen in the general public in the coming
>>> years if this proposal is adopted.
>>
>> A tad arrogant to think that SAA is a leader in developing opinion
>> among the "general public". There is no precedent for this view.
>> its time for me to get out of the conversation.
>
> Arrogant? So anyone who disagrees with you is now arrogant? I think
> you need to get a dictionary.
>

I was commenting solely on the visibility of SAA
to the general public. If you stopped 100 folks
on the street and asked them what SAA, likely none
would say sci.astro.amateur.

I'm sorry you took so much personal offense at
what I meant as a rational and sensible statement.

Phil

Date: 20 Aug 2006 13:15:11
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:
> Phil Wheeler wrote:
>> Greg Crinklaw wrote:
>>
>>> People are right to say, "What? You mean the moon of Pluto is
>>> now a planet, but Ganymede isn't? And I heard the moon would
>>> someday be a planet too!" The laughter about the silly
>>> astronomers has already begun!
>>>
>>
>> While the 70 ft, un-permitted flagpole Donald Trump recently installed
>> locally has gotten a fair amount of attention and letters to local
>> newspapers, I've yet to see *one* letter on this topic. The
>> "laughter" seems very muted amongst non-astronomers.
>
> What planet do you live on? :-) I mean, are you claiming I'm imagining
> things? How absurd.
>
> I've seen many examples of ridicule already, including posts made to
> this forum and a link to a cartoon posted just today. SAA is the front
> line, so to speak. The comments you see here are an advance view of
> what is going to happen in the general public in the coming years if
> this proposal is adopted.

Yes, ridicule is the first step towards truth.
>
> What I see in this day on SAA is that the real discussion has ended. Now
> the people who were on the periphery are sniping at bits and pieces of
> what was said, in rather nonconstructive and unnecessary ways.

Violent opposition is the second step.

> In other words, its time for me to get out of the conversation.

That's self evident.

http://cosmic.lifeform.org/?p=166

Date: 20 Aug 2006 12:41:34
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Date: 20 Aug 2006 12:04:39
From: Thomas Lee Elifritz
Subject: Greg Crinklaw is a Fascist Anti-Science Freak

Greg Crinklaw wrote:

> You are wrong that the current proposal is based on science.

Sure it is, Greg. This is how science works. We can either go forward,
with a solar system with more and ever interesting planets, and indeed
more solar systems with ever more bizarre structures, or we can go
backwards, with a solar system with less planets.

Your position is clear.

http://cosmic.lifeform.org/?p=166

Date: 20 Aug 2006 18:15:23
From:
Subject: Re: Soon 12 planets in the solar system !

The problem is that the definition is still too vague as to "What's a
planet". Here's what I'd do:

To be a planet, a body must be a sphere, orbit the Sun, have an
atmosphere, have a unique orbit, as follows:

-Have enough mass to form, basically, a sphere
-Orbit the Sun (or its Sun)
-Have an atmosphere (an atmosphere being gasses) of at least 3 km in
thickness
-Have a unique orbit, in other words no other significant planetoid
orbiting within 1.5 light minutes (about 30 million kilometers) of
your orbital path (moons don't count as 'orbiting in your path')
-A double or triple planet can exist if all planetoids meet the above
rules AND the center of their 'orbits' does not lie within any of the
planets' atmospheres/lithospheres; if it does, you've got one planet
and some moons

Would this preclude Pluto? Maybe, I'm not sure. But Xena, Charon, our
Moon, Ceres all are asteroids and moons.

Date: 20 Aug 2006 15:19:29
From: Ed
Subject: Re: Soon 12 planets in the solar system !

Thomas you need to find a good shrink sadly, just like Min.

Date: 20 Aug 2006 19:20:12
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:

> Thomas you need to find a good shrink sadly, just like Min.

In that case why don't you fill us in on the horrible mistake and the
great cost that will result from Pluto remaining a planet.

Inquiring minds want to know.

http://cosmic.lifeform.org

Date: 20 Aug 2006 11:04:42
From: Ed
Subject: Re: Soon 12 planets in the solar system !

Yes it does indicate a priceless astronomy bonanza...
not for astronomers however but for everyone who thinks
the world is going crazy including the comics...

Such as....

Did you hear the one about the Astronomer who tried to figure out
what the definition of the word planet means?

It took them 76 years to get one and they still haven't quite decided.

Maybe that means our next edition of Websters Dictionary won't be out
until 76 years from now!!!

I respect IAU Astronomers a heck of a lot now as they are really being
most logical.

Date: 20 Aug 2006 13:08:47
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:

> Yes it does indicate a priceless astronomy bonanza...
> not for astronomers however but for everyone who thinks
> the world is going crazy including the comics...

The world is going crazy, but it isn't the astronomers doing it.

I can see how that is the best you can do being the idiot that you are.

[snip]

> I respect IAU Astronomers a heck of a lot now as they are really being
> most logical.

Yes, I know how the concept of change is completely alien to you.

http://cosmic.lifeform.org/?p=97

Date: 21 Aug 2006 17:00:46
From:
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw ha escrito:

> You are wrong that the current proposal is based on science.

Where did I say that? I would never make such a fuzzy and naive
statement.

All I say is that the IAU proposal is a RATIONAL (and nothing but *just
that*!) solution to the problem of defining a planet.

> It is
> simply an ad hoc classification that makes arbitrary divisions. In
> reality, using "roughly spherical" as a distinction is no less arbitrary
> than using the orbit or mass of Pluto. It has no physical meaning
> beyond being something that can be defined.

The definition of species in taxonomy is also partly arbitrary. What
counts, is that the definition is practical for science (and not for
public comprehension).

And definitions of natural objects (rather than processes) based on
mathematics (e.g. in the case of planets: perfect roundnes) are unheard
of in science. This is because mathematics assumes perfection, while
natural objects are intrinsically non-perfect.

Science is not objective, but it rather tries to reduce the natural
subjective, emotional and irrational tendencies in our thinking to a
minimum. Pure objectivity is impossible to the human ape. But this does
not mean that we should give free reign to our arbitrarieness.

And taking Pluto, i.e. the second most massive KBO known, as the lower
cutoff point for the mass of a planet is about as arbitrary as you can
get. There exists absolutely no rational justification for this.

>
> The real problem with this proposed solution is that it causes trouble.
> Real world trouble for lots of people, from educators to planetaria to
> software developers.

The educators and planetaria will just have to adapt to what is,
instead of lamenting about what ought to be.

And actually, their trouble could not get worse than it is right now.
Many planetariums have started to use the term "unofficial name Xena"
for 2003UB313, since the latter term is a tongue twister impossible to
remember for a lay person. How long is this supposed to keep going on?

And as far as the software developers are concerned, they should just
get down on their lazy butts. In times where you can program artificial
intelligence, it cannot be so difficult to just change a few labels. If
they can=B4t, they should just look for another job (how about baking
pizza?). This is obstinate lazyness.

> It also exposes the astronomical community to
> ridicule.

The ridiculousness stems from the fact that astronomers have been
incapable to name a solar system object bigger than Pluto which they
have discovered more than a year ago.

> We would forever be arguing about which KBO is a planet (or
> not) and adding planets to an ever growing list.

We would not. Read again what I wrote in the article to which you are
responding here:
"=2E.. the simplest possible answer to the question of "how many planets
are there in our solar system?" is: "There are lots of planets in our
solar system. We don=B4t know exactly how many there are. We can only
estimate their number. Every year we discover new planets or candidates
for being planets. It=B4s just like with comets"."

When there exists only an approximate number of planets, then a change
in number of actually identified planets is of little relevance. Is
this too logical for a computer programmer to understand?

The idea of a fixed number of planets should be reserved to astrologers
and other idiots.

> People are right to
> say, "What? You mean the moon of Pluto is now a planet, but Ganymede
> isn't? And I heard the moon would someday be a planet too!" The
> laughter about the silly astronomers has already begun!

Who laughs last.....
If people wouldn=B4t generally be such idiots, then we wouldn=B4t be such
a ridiculous species. I am not ashamed for being an (amateur)
astronomer, I am ashamed for being a homo sapiens (spare me the
details, they don=B4t belong in this forum).

And the above comment is as silly as you would expect from ordinary
people (good guess on your side!) because it A) is based on the (non
scientific) criteria of "big" and "small" (see the article to which you
are responding here) and B) is based on ignorance, because the Sun will
blow up before the Moon has gotten away from Earth far enough to be
considered as a planet (do I have to explain what that will mean?).

>
> That's a high price to pay.
>
> I am willing to pay that price. But we need to get something worthwhile
> in return for it. A classification scheme based on how the bodies form,
> where they form, or what they are primarily composed of, would be a real
> science-based model.

The criterion of how bodies form is based on theory and not on
observation. It thus stands on porcelain feet.

And "primarily composed of" is in the same leage as "roughly sperical".
Besides that, the composition of just the classical planets is vastly
divergent.

> I would be willing to pay the high price for that.
> I am reluctant to pay such a high price for something that amounts to
> little more than an arbitrary political compromise!

In the article to which you are responding here I said that the only
political compromise I can see in the IAU proposal is the distinction
between "classical" and "dwarf planets". You should have responded to
that instead of just restating your opinion.

>
> ph42@infocanarias.com wrote:
> >> This proposal fails on all counts!
> >>
> >> I sure hope they wake up.
> >
> > .....says someone who apparently insists on staying asleep. Above all,
> > you must remember the following (I repeat, and it seems like that I
> > have to do it in capital letters):
> >
> > YOU CANNOT CALL PLUTO A PLANET WITHOUT CALLING 2003UB313 A PLANET AS
> > WELL. IT=B4S EITHER BOTH OR NONE.
> >
> > If you know of a better way to deal with this fact than the IAU then
> > please let us (an above all, the IAU) know.
>
> I have taken the time to make to propose two different solutions that I
> feel are better on different threads.

This comment is as useless as a hole in the kneecap, as long as you
don=B4t mention the name of the thread(s) and the date(s) of your posts.

Or are you perhaps referring yourself to the definition you gave on the
18th of this month in thread "YADOP: Yet Another Definition of Planet"
("I define a planet as any non-stellar body larger than a dust grain
that orbits a star, either directly or indirectly")? As Chris Peterson
correctly mentioned at the (present) end of that thread: "Surely the
whole point of this thread was to be a little bit silly...". I sure
hope that you agree with him.

> I also feel that the alternative
> solution under consideration by the IAU is a better choice.

Which altenative solution? I haven=B4t heard of any. And please give the
source (preferrably online).

> Regardless,
> claiming that someone who has no better solution somehow gives up their
> right to call a bad a solution a bad solution, is specious.

You are perfectly entitled to call a bad solution a bad solution. And
perhaps there doesn=B4t even exist a perfect solution in this case. But
a bad solution is still much better than no solution at all. So we are
obliged to be constructive in this case. I agree that the IAU proposal
might need a few patch-ups, but:

What I sure don=B4t want is three more years (until the next general
assembly of the IAU) of having to say "2003UB313". Can you say
"2003UB313" ten times rapidly without spitting? I have in fact been
practising it. And I would also like to get rid of that term "Kuiper
Belt Object", since it sounds so exotic that few laypersons can
remember it.=20

Peter

Date: 21 Aug 2006 17:57:10
From: Brian Tung
Subject: Re: Soon 12 planets in the solar system !

> > I also feel that the alternative
> > solution under consideration by the IAU is a better choice.
>
> Which altenative solution? I haven't heard of any. And please give the
> source (preferrably online).

I don't know if this is what Greg is talking about, but there was a
recent proposal, hastily submitted by Steven Soter, that suggests
discriminating between planets on the basis of mean dynamics. There is
some physical rationale (which I haven't yet examined) for the
discriminant M/sqrt(T), where M is the mass of the body and T its period
of revolution around the Sun. When measured in Earth masses and years,
there is no known body in the range

0.0002 < M/sqrt(T) < 0.05

whereas there are quite a few objects in similarly-sized ranges on
either side of that gap. The range is bounded by Mars (an undoubted
planet) at the high end, and 2003 UB313 on the low end. This proposal
is certainly interesting, and unlike the original IAU proposal, it is
both precise and fairly straightforwardly suggested by the available
data. What is of some concern is whether we understand planetary
dynamics well enough to say that the gap isn't just an artifact of a
limited data set.

I don't have a link to the article handy, but it is called, strangely
enough, "What is a Planet?" and it was submitted to The Astronomical
Journal on 2006-08-16.

--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

Date: 23 Aug 2006 22:22:35
From: Kevin Heider
Subject: Re: Soon 12 planets in the solar system !

On Mon, 21 Aug 2006 17:57:10 -0700 (PDT), brian@isi.edu (Brian Tung)
wrote:

>> > I also feel that the alternative
>> > solution under consideration by the IAU is a better choice.
>>

>I don't know if this is what Greg is talking about, but there was a
>recent proposal, hastily submitted by Steven Soter, that suggests
>discriminating between planets on the basis of mean dynamics. There is
>some physical rationale (which I haven't yet examined) for the
>discriminant M/sqrt(T), where M is the mass of the body and T its period
>of revolution around the Sun. When measured in Earth masses and years,
>there is no known body in the range
>
> 0.0002 < M/sqrt(T) < 0.05
>
>whereas there are quite a few objects in similarly-sized ranges on
>either side of that gap. The range is bounded by Mars (an undoubted
>planet) at the high end, and 2003 UB313 on the low end. This proposal
>is certainly interesting, and unlike the original IAU proposal, it is
>both precise and fairly straightforwardly suggested by the available
>data. What is of some concern is whether we understand planetary
>dynamics well enough to say that the gap isn't just an artifact of a
>limited data set.
>
>I don't have a link to the article handy, but it is called, strangely
>enough, "What is a Planet?" and it was submitted to The Astronomical
>Journal on 2006-08-16.

Brian;

I assume that you have found the article by now. But if you have not
(or for others), the link for Steven Soter's "What is a Planet?"
article is:

http://arxiv.org/ftp/astro-ph/papers/0608/0608359.pdf

An interesting note that I read elsewhere on the net:

Two planets in Gliese 876 system do come very close to each other
but they are protected by 1:2 harmonic orbit, so there is no way
they can collide with each other. That is the point of Steven Soter's
work,planets are object that made their orbits "safe" so to speak,
either by scattering smaller masses out of its orbital zone in a
Hubble time,or by influencing other planet's orbit in such way that
they orbit togetherin resonance. Anyway, planets do have "safe"
orbits.

Data on Gliese 876 system, notice how planet Gliese 876 c takes 30
daysto orbit star, while other planet in system - Gliese 876 b takes
60 daysto orbit the same star, so they are in 1:2 harmonic orbit,
and can never collide with each other:

============

1:2 harmonic orbit

Gliese 876 star.

Planet Gliese 876 c:
-------------------
http://www.extrasolar.net/planettour...l&PlanetID=156
Mass ( M sin i ): 0.56 Jupiters
Periastron Distance: 0.09 AU
Mean Distance: 0.13 AU
Apastron Distance: 0.16 AU
Orbital Period: 30.12 Days
Eccentricity: 0.27
Gravitational Influence
(Hill Sphere): 0.01 AU / 1600000 km

Planet Gliese 876 b:
-------------------
http://www.extrasolar.net/planettour...mal&PlanetID=2
Mass ( M sin i ): 1.935 � 0.007 Jupiters
Mean Distance: 0.207 � 0.00003 AU
Orbital Period: 60.94 � 0.013 Days
Eccentricity: 0.0249 � 0.0026
Gravitational Influence
(Hill Sphere): 0.025 AU / 3850000 km

Pluto is a very interesting binary KBO.

Can we call Pluto a Supermassive Asteroid? :-) (I'm just kidding
people.)

-- Kevin Heider

West Coast Swing Photos at:
http://www.pbase.com/kheider

Date: 23 Aug 2006 22:29:21
From: Brian Tung
Subject: Re: Soon 12 planets in the solar system !

Kevin Heider wrote:
> Brian;
>
> I assume that you have found the article by now. But if you have not
> (or for others), the link for Steven Soter's "What is a Planet?"
> article is:
>
> http://arxiv.org/ftp/astro-ph/papers/0608/0608359.pdf

I had the article; what I didn't have was the URL for it, since I had
downloaded the article and then discarded the link. Thanks for finding
it.

--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

Date: 22 Aug 2006 08:40:41
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

Another person looking for a mean-spirited name-calling argument rather
than good natured honest debate.

Sigh.

ph42@infocanarias.com wrote:
[obnoxiousness snipped]

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 22 Aug 2006 09:45:57
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw wrote:

> Another person looking for a mean-spirited name-calling argument rather
> than good natured honest debate.
>
> Sigh.

Tell us about the HORRIBLE COSTS of Pluto remaining a planet.

You know, I think I'm going to have to go with the little schoolchildren
on this one. Yes, I would believe little schoolchildren before I would
believe anything you would say here. Now why don't you go out and find a
nice sidewalk somewhere, and set up your telescope, and start being
educated by some of those children.

http://cosmic.lifeform.org

Date: 22 Aug 2006 13:31:31
From:
Subject: Re: Soon 12 planets in the solar system !

Greg Crinklaw ha escrito:

> Another person looking for a mean-spirited name-calling argument rather
> than good natured honest debate.
>
> Sigh.
>
> ph42@infocanarias.com wrote:
> [obnoxiousness snipped]

p=2E..@infocanarias.com wrote what? Which obnoxiousness are you referring
yourself to? Have I been name-calling you? If yes, please tell me where
I did it and I will apologize to you. Because as of right now I do not
see any reason why I should despise you.

But if you should be referring yourself to what I responded to a
certain illiterate creature on this forum, then I don=B4t see any reason
to apologize. Because I would be apologizing to it and not to you. Just
look at what it wrote in its reply to Carsten above: "If the IAU
decides to demote Pluto & UB313....". Demote 2003UB313?! It appears as
if it has no idea about what it is talking....

The most annoying thing is that these creatures are fairly numerous
among (not only) amateur astronomers. And to me, science - and above
all biology and astronomy - is something of a last refuge from that
irrational zoo in which we are obliged to live. Since science is done
by human beings, you cannot completely defend it from irrationality.
But if irrationality threatens to get the upper hand in an essential
aspect in one of the above two sciences, then I do in fact turn
furious. Because it is like they are trying to take away my last refuge
from human sillyness. As I said in my last response to you: "I am not
ashamed for being an (amateur) astronomer, I am ashamed for being a
homo sapiens".

And please note the distinction I make between ignorance and stupidity
in my response of 8-20 to you in this thread. This world is too complex
to know everything about everything, so we are all forced to be part
ignorant. I, for example, would never post to a forum on soccer, just
like that creature should not post to this forum. But my impression is,
that it is *deliberately* ignoring data. And as I said on 8-20 to you:
"=2E.deliberate ignorance (that is, deliberately ignoring available data)
is stupidity". The difference between ignorance and just plain
stupidity is very, very important to me.

If this offends you, then please tell me why.

Peter

Date: 23 Aug 2006 07:58:50
From: Ed
Subject: Re: Soon 12 planets in the solar system !

I'm leaving just as David Levy, Jim Scotti and a host of others have
already left.
But I will leave you with a quote from an Op-Ed in yesterday's Science
Times:

"The sky is our oldest symbol of order and regularity in nature. Mess
with it at your own peril."

Date: 24 Aug 2006 01:22:49
From: Carsten A. Arnholm
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:
> I'm leaving just as David Levy, Jim Scotti and a host of others have
> already left.
> But I will leave you with a quote from an Op-Ed in yesterday's Science
> Times:
>
> "The sky is our oldest symbol of order and regularity in nature. Mess
> with it at your own peril."

You mean, like
http://www.palantir.net/2001/tma1/wav/goodbye.wav

?

Date: 23 Aug 2006 18:08:30
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:
>
> "The sky is our oldest symbol of order and regularity in nature. Mess
> with it at your own peril."
>

Similar words might well have been spoken to Galileo.

Phil

Date: 23 Aug 2006 18:05:32
From: Phil Wheeler
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:
> I'm leaving just as David Levy, Jim Scotti and a host of others have
> already left.

To where, I wonder?

Phil

Date: 23 Aug 2006 12:08:06
From: Greg Crinklaw
Subject: Re: Soon 12 planets in the solar system !

Phil Wheeler wrote:
> Ed wrote:
>> I'm leaving just as David Levy, Jim Scotti and a host of others have
>> already left.
>
> To where, I wonder?

Not to mention where from?

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://www.skyhound.com/sh/comets.html

To reply take out your eye

Date: 23 Aug 2006 12:35:29
From: Thomas Lee Elifritz
Subject: Re: Soon 12 planets in the solar system !

Ed wrote:

> I'm leaving just as David Levy, Jim Scotti and a host of others have
> already left.

Bye now! Don't come back.

> But I will leave you with a quote from an Op-Ed in yesterday's Science
> Times:
>
> "The sky is our oldest symbol of order and regularity in nature. Mess
> with it at your own peril."

Other solar systems in the universe would seem to disagree.

Naming something isn't going to change it.

http://cosmic.lifeform.org

Date: 16 Aug 2006 14:08:19
From: Chris L Peterson
Subject: Re: Soon 12 planets in the solar system !

On Wed, 16 Aug 2006 12:20:22 +0200, <Thierry > wrote:

>Soon there will be probably 12 planets in the solar system...

Those IAU guys are nuts; what a waste of time!

I predict there will continue to be nine planets in the Solar System. At
the most these "formal" definitions will cause a few authors of
technical papers to shift their terminology. The rest of the world will
carry on as always.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 16 Aug 2006 06:43:24
From: Don't Be Evil
Subject: Re: Soon 12 planets in the solar system !

Don't Be Evil wrote:
> Thierry wrote:
> > Hi,
> >
> > Soon there will be probably 12 planets in the solar system !
> > ercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto,
> > Charon and 2003 UB313
> > See the latest IAU news at :
> > http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html
> >
> > It is amazing that knowing that the definition states that "A planet is a
> > celestial body that (a) has sufficient mass for its self-gravity to overcome
> > rigid body forces so that it assumes a hydrostatic equilibrium (nearly
> > round) shape, and (b) is in orbit around a star, and is neither a star nor a
> > satellite of a planet." that IAU committee has considered Charon as a true
> > planet... Isn't it the satellite of a planet itself orbiting the Sun ?
> > And the Moon is this case ? In-betwene lines, IAU's definition means that a
> > body has to show a mass over about 5x10^20 kg, and show a diameter > 800 km
> > or so. The Moon is round, and close to 3400 km in diameter... !
> >
> > I wonder what does Michael Brown (who is not member of IAU) think of this
> > idea paradox (I image his answer, it is not more a question for astronomers
> > but only administrative).
> >
> > Anyway, in all cases that will be always the status quo for amateurs... ;-)
> >
> > Have a clear and dark sky (as far as possible;..)
> >
> > Thierry
> > http://www.astrosurf.org/lombry
>
> Mike Brown has posted an analysis:
> http://www.gps.caltech.edu/~mbrown/whatsaplanet/howmanplanets.html
>
> I'll add the Charon's best claim to being a planet isn't Pluto's
> relatively small size, but that it's (probably) a captured KBO. As are
> several of the outer planet's moons. Look at Triton, for example.

And:
http://www.gps.caltech.edu/~mbrown/whatsaplanet/

Date: 16 Aug 2006 06:19:22
From:
Subject: Re: Soon 12 planets in the solar system !

The IAU definition says:

> "2 For two or more objects comprising a multiple object system, the
> primary object is designated a planet if it independently satisfies the
> conditions above. A secondary object satisfying these conditions is
> also designated a planet if the system barycentre resides outside the
> primary.

Thierry wrote:

> I am agree with any definition, but between us, is it logical ?
...
> But up to now, the common sense - which of course is not a scientific
> concept, tells that any object orbiting a planet is a satellite.

Whether the definition *really* makes sense will have to wait until we
know
more about how planets and satellites (to say nothing of stars!) form.

But whether you agree with it or not, the definition is clever and
farsighted.
Remember, we'll be finding lots more KBOs out there, and learning more
about the KBOs that have been found. With a 10:1 mass ratio, common
sense says that Charon is Pluto's satellite. But what if the mass ratio
were 2:1? What about 1.5:1, or 1:1? How much money would you bet
that we *won't* find a system like that?

- Tony Flanders

Date: 16 Aug 2006 15:38:56
From:
Subject: Re: Soon 12 planets in the solar system !

<tony_flanders@yahoo.com > wrote in message
news:1155734360.814689.207190@m79g2000cwm.googlegroups.com...
> The IAU definition says:
>...

> Thierry wrote:
>
>> I am agree with any definition, but between us, is it logical ?
> ...
>> But up to now, the common sense - which of course is not a scientific
>> concept, tells that any object orbiting a planet is a satellite.
>
> Whether the definition *really* makes sense will have to wait until we
> know
> more about how planets and satellites (to say nothing of stars!) form.
>
> But whether you agree with it or not, the definition is clever and
> farsighted.
> Remember, we'll be finding lots more KBOs out there, and learning more
> about the KBOs that have been found. With a 10:1 mass ratio, common
> sense says that Charon is Pluto's satellite. But what if the mass ratio
> were 2:1? What about 1.5:1, or 1:1? How much money would you bet
> that we *won't* find a system like that?

Hi Tom,

For sure idem for some KBO, many have probably a rounded shape and are
probably as big as Charon, etc.
I also read all the litterature about the definition of a planet including
Michael Brown's pages, etc.
I am nothing against IAU definition including mass, radius and barycenter
which is very smart and clear but on another side one speeks of the
"Earth-Moon couple", isn't it, and more than one physicist consider it as a
true physical couple due to their size and proximity.... where ever could be
the barycenter...

Thierry

>
> - Tony Flanders
>

Date: 16 Aug 2006 06:18:47
From: Don't Be Evil
Subject: Re: Soon 12 planets in the solar system !

Thierry wrote:
> Hi,
>
> Soon there will be probably 12 planets in the solar system !
> ercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto,
> Charon and 2003 UB313
> See the latest IAU news at :
> http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html
>
> It is amazing that knowing that the definition states that "A planet is a
> celestial body that (a) has sufficient mass for its self-gravity to overcome
> rigid body forces so that it assumes a hydrostatic equilibrium (nearly
> round) shape, and (b) is in orbit around a star, and is neither a star nor a
> satellite of a planet." that IAU committee has considered Charon as a true
> planet... Isn't it the satellite of a planet itself orbiting the Sun ?
> And the Moon is this case ? In-betwene lines, IAU's definition means that a
> body has to show a mass over about 5x10^20 kg, and show a diameter > 800 km
> or so. The Moon is round, and close to 3400 km in diameter... !
>
> I wonder what does Michael Brown (who is not member of IAU) think of this
> idea paradox (I image his answer, it is not more a question for astronomers
> but only administrative).
>
> Anyway, in all cases that will be always the status quo for amateurs... ;-)
>
> Have a clear and dark sky (as far as possible;..)
>
> Thierry
> http://www.astrosurf.org/lombry

Mike Brown has posted an analysis:
http://www.gps.caltech.edu/~mbrown/whatsaplanet/howmanplanets.html

I'll add the Charon's best claim to being a planet isn't Pluto's
relatively small size, but that it's (probably) a captured KBO. As are
several of the outer planet's moons. Look at Triton, for example.

Date: 16 Aug 2006 17:31:39
From:
Subject: Re: Soon 12 planets in the solar system !

"Don't Be Evil" <g626700-gg@yahoo.com > wrote in message
news:1155734327.644875.187700@p79g2000cwp.googlegroups.com...
>
> Thierry wrote:
>> Hi,
>>
>...

> Mike Brown has posted an analysis:
> http://www.gps.caltech.edu/~mbrown/whatsaplanet/howmanplanets.html
>
> I'll add the Charon's best claim to being a planet isn't Pluto's
> relatively small size, but that it's (probably) a captured KBO. As are
> several of the outer planet's moons. Look at Triton, for example.
>

I just have the confirmation by Owen Gingerich from IAU.
The Planet committee has simply defined the rules, but not draw up the list
yet. Another committee from the Solar System Division of
the IAU will work on the list if the resolution passes next week.

Thierry

Date: 16 Aug 2006 06:13:07
From:
Subject: Re: Soon 12 planets in the solar system !

What I found interesting about the draft resolution is that they
included Ceres in the list of regular (not plutons) planets, I guess
because it is big enough to be perfectly round.

Clif Ashcraft

Date: 16 Aug 2006 15:43:51
From:
Subject: Re: Soon 12 planets in the solar system !

<WA2GUF@optonline.net > wrote in message
news:1155733986.921891.211380@i42g2000cwa.googlegroups.com...
> What I found interesting about the draft resolution is that they
> included Ceres in the list of regular (not plutons) planets, I guess
> because it is big enough to be perfectly round.
>
For sure, IAU definition means that the planet shows a mass say over 5x10^20
kg, diam. over 800 km or so and a barycenter outside the host planet.
Ceres is ...9.5x10^20 kg, 933 km in diameter...

An I wonder why Quaoar (10^21 kg, 1260 km) and others are not included then.
Probably because they are included in the KBO family and alike.

Thierry

> Clif Ashcraft
>

Date: 16 Aug 2006 06:10:59
From: Don't Be Evil
Subject: Re: Soon 12 planets in the solar system !

Stan Jensen wrote:
> And no mention of Quaoar or Senda. And I think there's one other one
> out there, starts with a "V"?

It's Sedna, and there are hundreds of other distant objects out there
larger than Ceres. Most don't have names.

Date: 16 Aug 2006 06:09:19
From: Don't Be Evil
Subject: Re: Soon 12 planets in the solar system !

Thierry wrote:
> "robin_astro" <robin_astro@hotmail.com> wrote in message
> news:1155727762.075336.4400@m73g2000cwd.googlegroups.com...
> >
> > Starlord wrote:
> >> is neither a star nor a
> >> > satellite of a planet."
> >>
> >> That takes Pluto's 3 moons and our moon out of the planet class.
> >>
> >>
> >
> > Nope. They have covered this. Charon is a planet (part of a double
> > planetary system) The other moons stay planetary satellites.
> >
> > Quote from IAU draft resolution
> > http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_resolution.html
> >
> > "2 For two or more objects comprising a multiple object system, the
> > primary object is designated a planet if it independently satisfies the
> > conditions above. A secondary object satisfying these conditions is
> > also designated a planet if the system barycentre resides outside the
> > primary.
>
> I am agree with any definition, but between us, is it logical ?
> I suspect they made the comparison with stellar binary systems to arrive to
> this conclusion.
> They simply apply to planets what exists for stars... so that all celestial
> objects are included in the definition
> But up to now, the common sense - which of course is not a scientific
> concept, tells that any object orbiting a planet is a satellite.
> With their new definition, that means that is not only the gravitational
> mass and radius that are taken into account but also the distance to the
> host object. For me it is no more logical. Soon Jupiter-like exoplanets will
> lost their psosible satellites because they are so-called outside the
> barycenter !...
>
> Thierry
>
> Secondary objects not satisfying these criteria are
> > "satellites". Under this definition, Pluto's companion Charon is a
> > planet, making Pluto-Charon a double planet."
> >
> > Looks like the IAU are going to have to rename the Minor Planets Centre
> > though!
> >
> > Robin
> >

It might make sense to refer to Pluto/Charon as a binary planet, but
Charon can't be considered one on its own. Triton is far larger, but
won't be counted because it orbits a larger planet (Neptune).

Date: 16 Aug 2006 05:53:57
From: Ed
Subject: Re: Soon 12 planets in the solar system !

Rich,

Say you discovered Pluto and what would you think after 76 years that
it was going to be demoted?

I don't think you would like it either.

Personally, I thought just saying Pluto is the lower limit might have
been fine.
To demote it to me at least is like saying that Websters dictionary ...

Waits a full 76 years until it includes a new word and it's definition
which would make
Astronomers look pretty ridiculous.

Date: 16 Aug 2006 04:29:22
From: robin_astro
Subject: Re: Soon 12 planets in the solar system !

Starlord wrote:
> is neither a star nor a
> > satellite of a planet."
>
> That takes Pluto's 3 moons and our moon out of the planet class.
>
>

Nope. They have covered this. Charon is a planet (part of a double
planetary system) The other moons stay planetary satellites.

Quote from IAU draft resolution
http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_resolution.html

"2 For two or more objects comprising a multiple object system, the
primary object is designated a planet if it independently satisfies the
conditions above. A secondary object satisfying these conditions is
also designated a planet if the system barycentre resides outside the
primary. Secondary objects not satisfying these criteria are
"satellites". Under this definition, Pluto's companion Charon is a
planet, making Pluto-Charon a double planet."

Looks like the IAU are going to have to rename the Minor Planets Centre
though!

Robin

Date: 16 Aug 2006 13:13:13
From: Paul Schlyter
Subject: Re: Soon 12 planets in the solar system !

The solar system had 12 planets already some 160 years ago.....

After the discovery of (4) Vesta in 1807, no more asteroids were discovered
for 38 years, until (5) Astraea was discovered in 1845.

Then Neptune was discovered in 1846.

Then (6) Hebe was discovered in 1847 .... and since then, new asteroids
were discovered almost each and every year.

But from 1807 to 1844 only 4 asteroids were known. They were counted
among the planets -- thus the solar system had 11 known planets during
this time period. In 1845, the 12th planet, Astraea, was discovered,
and in 1846, the 13th planet, Neptune, was discovered.

In the years following 1846, many more small planets were discovered.
The word "planet" was redefined so it included only the major planets,
reducing the number of known planets in the solar system to 8.

Now, when the word "planet" is about to be redefined again, the solar
system may get 12 known planets for the second time....

--
------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://stjarnhimlen.se/

Date: 16 Aug 2006 08:24:35
From: Stan Jensen
Subject: Re: Soon 12 planets in the solar system !

And no mention of Quaoar or Senda. And I think there's one other one
out there, starts with a "V"?

Date: 16 Aug 2006 14:23:19
From:
Subject: Re: Soon 12 planets in the solar system !

"robin_astro" <robin_astro@hotmail.com > wrote in message
news:1155727762.075336.4400@m73g2000cwd.googlegroups.com...
>
> Starlord wrote:
>> is neither a star nor a
>> > satellite of a planet."
>>
>> That takes Pluto's 3 moons and our moon out of the planet class.
>>
>>
>
> Nope. They have covered this. Charon is a planet (part of a double
> planetary system) The other moons stay planetary satellites.
>
> Quote from IAU draft resolution
> http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_resolution.html
>
> "2 For two or more objects comprising a multiple object system, the
> primary object is designated a planet if it independently satisfies the
> conditions above. A secondary object satisfying these conditions is
> also designated a planet if the system barycentre resides outside the
> primary.

I am agree with any definition, but between us, is it logical ?
I suspect they made the comparison with stellar binary systems to arrive to
this conclusion.
They simply apply to planets what exists for stars... so that all celestial
objects are included in the definition
But up to now, the common sense - which of course is not a scientific
concept, tells that any object orbiting a planet is a satellite.
With their new definition, that means that is not only the gravitational
mass and radius that are taken into account but also the distance to the
host object. For me it is no more logical. Soon Jupiter-like exoplanets will
lost their psosible satellites because they are so-called outside the
barycenter !...

Thierry

Secondary objects not satisfying these criteria are
> "satellites". Under this definition, Pluto's companion Charon is a
> planet, making Pluto-Charon a double planet."
>
> Looks like the IAU are going to have to rename the Minor Planets Centre
> though!
>
> Robin
>

Date: 16 Aug 2006 23:43:53
From: Carsten A. Arnholm
Subject: Re: Soon 12 planets in the solar system !

robin_astro wrote:
> Starlord wrote:
>> is neither a star nor a
>>> satellite of a planet."
>>
>> That takes Pluto's 3 moons and our moon out of the planet class.
>>
>>
>
> Nope. They have covered this. Charon is a planet (part of a double
> planetary system) The other moons stay planetary satellites.

Hi Robin :-)

But the two small moons (Nix and Hydra) can't be planetary satellites, since
they don't orbit a planet, but instead orbit the barycentre of Pluto and
Charon? Don't they?

barycentric satellites?

--
Carsten A. Arnholm
http://arnholm.org/
N59.776 E10.457

Date: 16 Aug 2006 04:18:51
From: Rich
Subject: Re: Soon 12 planets in the solar system !

Thierry wrote:
> Hi,
>
> Soon there will be probably 12 planets in the solar system !
> ercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto,
> Charon and 2003 UB313
> See the latest IAU news at :
> http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html
>
> It is amazing that knowing that the definition states that "A planet is a
> celestial body that (a) has sufficient mass for its self-gravity to overcome
> rigid body forces so that it assumes a hydrostatic equilibrium (nearly
> round) shape, and (b) is in orbit around a star, and is neither a star nor a
> satellite of a planet." that IAU committee has considered Charon as a true
> planet... Isn't it the satellite of a planet itself orbiting the Sun ?
> And the Moon is this case ? In-betwene lines, IAU's definition means that a
> body has to show a mass over about 5x10^20 kg, and show a diameter > 800 km
> or so. The Moon is round, and close to 3400 km in diameter... !
>
> I wonder what does Michael Brown (who is not member of IAU) think of this
> idea paradox (I image his answer, it is not more a question for astronomers
> but only administrative).
>
> Anyway, in all cases that will be always the status quo for amateurs... ;-)
>
> Have a clear and dark sky (as far as possible;..)
>
> Thierry
> http://www.astrosurf.org/lombry

Lets hope nostalgia over Pluto and it's discoverer does not have any
effect on a decision.

Date: 16 Aug 2006 03:48:23
From: Starlord
Subject: Re: Soon 12 planets in the solar system !

is neither a star nor a
> satellite of a planet."

That takes Pluto's 3 moons and our moon out of the planet class.

--
The Lone Sidewalk Astronomer of Rosamond

Telescope Buyers FAQ
http://home.inreach.com/starlord
Sidewalk Astronomy
www.sidewalkastronomy.info
Astronomy Net Online Gift Shop
http://www.cafepress.com/astronomy_net
In Garden Online Gift Shop
http://www.cafepress.com/ingarden
Blast Off Online Gift Shop
http://www.cafepress.com/starlords
Astro Blog
http://starlord.bloggerteam.com/

<Thierry > wrote in message news:44e2f161$1@news.vo.lu...
> Hi,
>

Date: 16 Aug 2006 16:19:41
From:
Subject: Re: Soon 12 planets in the solar system !

Paul Schlyter wrote:
> The solar system had 12 planets already some 160 years ago.....
>
> After the discovery of (4) Vesta in 1807, no more asteroids were discovered
> for 38 years, until (5) Astraea was discovered in 1845.

> Then Neptune was discovered in 1846.

> Then (6) Hebe was discovered in 1847 .... and since then, new asteroids
> were discovered almost each and every year.

> But from 1807 to 1844 only 4 asteroids were known. They were counted
> among the planets -- thus the solar system had 11 known planets during
> this time period. In 1845, the 12th planet, Astraea, was discovered,
> and in 1846, the 13th planet, Neptune, was discovered.

> In the years following 1846, many more small planets were discovered.
> The word "planet" was redefined so it included only the major planets,
> reducing the number of known planets in the solar system to 8.

> Now, when the word "planet" is about to be redefined again, the solar
> system may get 12 known planets for the second time....

Of course, since Quaoar and Sedna are likely *also* big enough to be
spherical, even if they aren't bigger than Pluto, as someone pointed
out, we may get more than 12.

Oh, and this site

http://aa.usno.navy.mil/hilton/AsteroidHistory/minorplanets.html

deals a bit more with this particular fascinating bit of history.

If it is decided to go the other way, perhaps it might be argued that
Pluto should be kept as a 'historic' planet - but then everything up to
Astraea should perhaps be kept too!

Of course, one might have a *three-tier* Solar System, in which Ceres,
being spherical, gets to be a 'minor planet', but all the rest of the
asteroids are now officially asteroids, or something like that.

John Savard

Date: 16 Aug 2006 15:57:56
From: robin_astro
Subject: Re: Soon 12 planets in the solar system !

Carsten A. Arnholm wrote:
> robin_astro wrote:
> > Starlord wrote:
> >> is neither a star nor a
> >>> satellite of a planet."
> >>
> >> That takes Pluto's 3 moons and our moon out of the planet class.
> >>
> >>
> >
> > Nope. They have covered this. Charon is a planet (part of a double
> > planetary system) The other moons stay planetary satellites.
>
> Hi Robin :-)
>
> But the two small moons (Nix and Hydra) can't be planetary satellites, since
> they don't orbit a planet, but instead orbit the barycentre of Pluto and
> Charon? Don't they?
>
> barycentric satellites?
>
Hi Carsten

This raises an interesting point about the location of the barycentre
of an n body system. eg in the hypothetical case of a figure of eight
orbit of 3 objects, the barycentre is alternately located at the centre
of each component in turn, moving from one to the other. Does this mean
the objects in such a system would alternate between being planets and
satellites?
see here for a simulation (Java)
http://faculty.ifmo.ru/butikov/Projects/Collection4.html

Robin

Date: 16 Aug 2006 16:20:23
From: Brian Tung
Subject: Re: Soon 12 planets in the solar system !

robin_astro wrote:
> This raises an interesting point about the location of the barycentre
> of an n body system. eg in the hypothetical case of a figure of eight
> orbit of 3 objects, the barycentre is alternately located at the centre
> of each component in turn, moving from one to the other. Does this mean
> the objects in such a system would alternate between being planets and
> satellites?

You don't even need that. If Pluto and Charon had orbits that were
elliptical enough, the barycenter could be alternately within and then
outside Pluto. I have to wonder if they're taking this into account,
and using qualifiers like "at perisides" or "at apsides" or "at a
distance equal to semi-major axis," or something like that.

--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
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Date: 17 Aug 2006 07:43:14
From: Paul Schlyter
Subject: Re: Soon 12 planets in the solar system !

In article <ec097n$ftq$1@praesepe.isi.edu >, Brian Tung <brian@isi.edu> wrote:

> robin_astro wrote:
>> This raises an interesting point about the location of the barycentre
>> of an n body system. eg in the hypothetical case of a figure of eight
>> orbit of 3 objects, the barycentre is alternately located at the centre
>> of each component in turn, moving from one to the other. Does this mean
>> the objects in such a system would alternate between being planets and
>> satellites?
>
> You don't even need that. If Pluto and Charon h