Pluto - Not a Planet?

[CerebralEcstasy]

I've been listening to many different opinions about this particular subject and thought to ask what my fellow hypographians thought about it.

 

http://abcnews.go.com/Technology/story?id=2312963&page=1

 

What say you?

[Mercedes Benzene]

I do not think that pluto should be considered a planet.

It is too unlike everything else in our solar system.

[Turtle]

I hear that the Big Boys & Girls (IAU - International Astonomers Union) are in Prague hashing out an official answer to the "is Pluto a planet" question as we post.

http://www.iau.org/

 

I think Pluto is no longer deserving of the title planet; call it a planetoid or asteroid & give it some class A status or some such. It is only unique now in terms of the first such far-distant-body identified.:eek: :D

[Tormod]

I thought Pluto was a dog?! What's going on here!

[cwes99_03]

What recommendations would those of us in the know give as requirements to title a celestial body as a planet?

 

I believe there needs to be some size requirements, though what these may be I'm not sure.

I also believe there should be a requirement on the value of the eliptical orbit (I forget the letter used in geometry for this value).

Also should there be a requirement for composition. One article I read suggested classification of planets similar to that of the stars - gas giant, ice dwarf, etc. This seems very similar to the classifications used in Star Trek of m,p,j,etc class planets.

Here's my question. What is the eliptical value of the orbit of Neptune? (I ask this because I can't remember whether Neptune's orbit is more eliptical or Pluto's but I know that their orbit paths overlap so that Pluto during certain times of the year is nearer the sun than Neptune. This has been used along with the size of Pluto to give cause for it being titled a planet. However, there are objects nearer the sun that have a near perfect circular orbit, but are much smaller than Pluto, and there are objects significan't larger than Pluto further out in orbit (which is why there is even a question in the first place.)

[Tormod]

It is Pluto's path that takes it inside that of Neptune. Also, Pluto's orbit lies at an inclination compared to the other planets, which suggests that it was not born in the same way as the planets, but rather pulled out of the Kuiper belt and ended up in a planet-like orbit.

[Jay-qu]

I heard that there was a possibility that pluto was once formed as a moon around neptune, and flung out by some interaction.

 

I dont think its a planet, because of the things already mentioned.

There was also another interesting thing to note that got said in my last lecture. As you move out from the sun each next orbit is in a similar ratio to that of the previous planets orbit, I am yet to test this, and apparently it is really rough, but pluto is way out. The kicker is that quoaor is at an orbit of approx the next ratio out after neptune, its orbit is also lying in the plane of the solar system and fairly circular. Do we then call that a planet?

[myspip90]

Haven't objects (not officially planets though) further away from Pluto been observed that are larger than pluto?

[CerebralEcstasy]

Haven't objects (not officially planets though) further away from Pluto been observed that are larger than pluto?

 

Yes, Zena for instance. Larger than Pluto, yet not considered a planet.

[Turtle]

This just in from Prauge: the Pluton!? :)

A NEW kind of planet, the "pluton", could soon be taking its place in the Solar System.

 

Astronomers have agreed on a draft proposal for redefining what constitutes a planet.

http://news.scotsman.com/scitech.cfm?id=1194292006

[Boerseun]

What's the big idea behind classifying something as a 'planet', in any case? If you think about it, Pluto is even smaller than our moon, yet is considered a planet because it revolves primarily around the sun. In my view, every object of any size that is the product of accretion over kazillions of years around a specific star could very well be termed a 'planet'. That, of course, will imply that we have well over a trillion planets. Inventing a mnemonic to remember their sequence will be a bit tough, though.

 

But any case - what is the fundamental difference between a rock in the asteroid belt and Jupiter, for instance? I'd say that Earth is better classified with the rock than with Jupiter. Earth and the rock have similar densities, similar composition, etc. Yet we are classified with Jupiter as 'planets', whilst Jupiter might very well be termed a 'failed star', or the sun's binary counterpart which failed to accrete enough hydrogen to light up.

 

Most stars in our galaxy seem to be in binary systems. This alone indicates that planets should be fairly common, seeing as more than one object can clearly form from the same accretion disk. So, what are planets, then? The residue of what would have formed the core of a star had only enough hydrogen been added in the forming stages?

 

This suggests a relation between pebbles and stars - or even as high as black holes. You start with two grains of dust that collide and stick. You add material, and before you know it, you have an asteroid. Any bigger, and you'll end up with a moon-sized object, big enough so that its gravity will self-regulate the debris from any susequent collisions to form a sphere. Any bigger than this, and you'll end up with an Earth-sized planet. And bigger still, you'll end up with a Jovian planet and if you keep adding mass, the whole thing will self-ignite under its own gravity and you'll have a star. Keep on adding mass and eventually the thing will collapse under its own weight and you'll end up with a black hole.

 

And the only change to your initial speck of dust that grew into a mighty black hole was simply adding mass.

 

So, does the classification of these objects as asteroids, moons, planets, and stars make any sense, apart from the obvious (the star is the burning one, the planet revolves around the star, the moon revolves around the planet) make any sense? Seeing as they're trying to blast Pluto as a planet, they should do it according to its orbit, and not its size. Size is immaterial. But in doing this, be have defined planets as sticking to a certain orbital quality. Then, one can ask, why is Venus the only planet that spins from East to West? What happened there? Should we now declassify Venus as a planet as well?

 

I think everything in orbit around our Sun, from the inner rocky planets to the outer Kuiper belt objects and even the Oort cloud, are deserving of the name "planet" to some degree. Because the borders between our classifications are very weak and full of holes, as the Pluto debacle clearly shows.

[ronthepon]

Really well said, Boerseun.

[Turtle]

I respectively respectably disagree with you last two gentlemen posters.:) :shrug: Did you read the entire reasoning the committee gave for the decision?

The IAU, responsible for the naming of planets and moons since 1919, set up a Planet Definition Committee (PDC) to consider the problem. Committee member Professor Richard Binzel said: "Our goal was to find a scientific basis for a new definition of planet, and we chose gravity as the determining factor.

 

"Nature decides whether or not an object is a planet."

http://news.scotsman.com/scitech.cfm?id=1194292006

 

:lol:

[Jay-qu]

do you really think nature decides?

 

Planet is a word, it is associated with objects, we choose what those objects may be by physical properties of said objects.

 

I think its just all caught up in semantics..

[Turtle]

do you really think nature decides?

 

Planet is a word, it is associated with objects, we choose what those objects may be by physical properties of said objects.

Oh good grief! :lol: It is simply an expression there, the use of the word nature. The natural physical property chosen for the planet definition is gravity and when a "space body" has enough mass so that its gravitational forces pull it into a sphere then that is the definition division of planet or pluton. It is not arbitrary at all as you imply, it is a progression of taxonomy.

[Boerseun]

...and when a "space body" has enough mass so that its gravitational forces pull it into a sphere then that is the definition division of planet or pluton...

In other words, all moons save those of Mars have now officially ceased to exist as 'moons', and are all now bona fide planets.

[Turtle]

In other words, all moons save those of Mars have now officially ceased to exist as 'moons', and are all now bona fide planets.

No no no...:lol: this has nothing to due with moons changing in the inner solar system. Moons orbit planets, & only Pluto is losing planet status to pluton status & so its so-called moon Charon raises to pluton status. Again...did ya read the whole article? Or are you guys just yankin' an old man's chain late at night>:shrug: