OT: The solar system has 12 planets
 

Astronomy.com Link
Wikipedia Link
International Astronomical Union Link

According to the committee set up to determine what the definition of a planet is, we now have 12 planets...pending approval from the IAU (International Astronomical Union) on August 26. If it's approved, the asteroid Ceres, Pluto's moon Charon and the Kuiper Belt Object UB313 will all be considered planets, bringing the total to 12. There's also about a dozen others that would be candidates for planetary status.

Cool, eh?

Re: OT: The solar system has 12 planets
 

They don't know what they are talking about. Its all a big conspiracy designed to scare us into believing that Earth is a uniqe planet and that we are all alone in the universe.

Re: OT: The solar system has 12 planets
 

Yes, and there is another planet in Earth's precise orbit exactly on the opposite side of the sun at all times so it can't be seen unless you leave the planet. http://forum.shrapnelgames.com/image...s/rolleyes.gif

Re: OT: The solar system has 12 planets
 

Yes. In colaberation with the civilization on that planet we developed stealth, fiber optics, silicon chips, etc...Truly. I read it some where. http://forum.shrapnelgames.com/images/smilies/smirk.gif

Re: OT: The solar system has 12 planets
 

its probably on the internet somewhere.... http://forum.shrapnelgames.com/image...s/rolleyes.gif

Re: OT: The solar system has 12 planets
 

Does no one have anything non-nonsensical to say? I know, that didn't make a whole lot of sense...oh well.

Re: OT: The solar system has 12 planets
 

UB13 should be renamed to something better. (Seriously, it sounds like something from the AvP universe.)

... Let's pitch some ideas.

Re: OT: The solar system has 12 planets
 

I assume you disagree with Xena rather than just UB313. I hope they choose something better otherwise in 1000 years a little girlboy asks her 4th clone father what does Xena mean.

Re: OT: The solar system has 12 planets
 

I've been reading a lot about this lately. Seems there's been a big ongoing debate over WHAT constitutes a planet, and what DOESN'T, and somewhere in the process even ol' Pluto almost ended up on the chopping block. For awhile there it was up in the air as to whether we had anywhere from 8 to 12 planets in our neck of the woods.

Re: OT: The solar system has 12 planets
 

I think the solution they came up with (include pluto etc) is a cop out. Pluto isn't a planet, it's a trans-neptunian ice-ball, and all that other junk out there should be given the same status. They should go even furher though: Having calssified those things as "ice worlds" they should reclassify saturn, jupiter, neptune and uranus as "gas giants", since they have very little in common with anything else currently called a "planet" and that leaves Mercury, Venus, Earth, Mars and Ceres to be the "Rock worlds." Things like Vespa which aren't even spherical should remain asteroids. Not sure wwhat to do with moons mind you - is our moon just a satellite or is it a rock world? I mean technically it's both, so what would you call it?

Re: OT: The solar system has 12 planets
 

Charon being included as a planet was a bit surprising. Well, we'll know in a week or so whether this new redefinition is approved by the vote. If more planets are discovered, we could end up with more than 12 in the future.

I can imagine that many years from now, I'll show my future kids my old astronomy book that shows only 9 planets, and I'll say, see, there were only 9 planets back then!

Re: OT: The solar system has 12 planets
 

If Pluto AND Charon are planets, then Luna should surely be a planet too.

Won't somebody think of the children?!

Re: OT: The solar system has 12 planets
 

Not by the proposed standard, which involves where the objects' barycenter is. If the point the objects orbit around is inside one of them (Earth-Luna), the other is a moon. If the barycenter is outside (Pluto-Charon), both are planets (if they're both round).

One of the objections to this new definition is that the number of planets in our solar system could be as high as 53. I'm not sure why that upsets some people, though.

Re: OT: The solar system has 12 planets
 

I think one of the criteria of a planet should be it's gravitational effect on the rest of the solar system. I had a solar system simulator at one point that showed that if you took any one of the 9 'classical' planets out of the solar system, then the other 8 planets went all squirrely. I have no idea what the magic cutoff point would be, but how many of the larger Kuiper Belt objects or even large asteroids (like Ceres) have that sort of effect?

Of course, according to Alf, the 10th planet in our system is named Alvin, not UB313

Re: OT: The solar system has 12 planets
 

That's quite a messy definition... If I recall correctly the barycenter is influenced by the distance between the two objects, not just their mass. By this definition Charon wouldn't have been a planet if it had been in a lower orbit. I can agree with the rest of the proposal but the Charon thing is a bit weird.

edit: just found this link:
http://oklo.org/?p=120#comments
Apperently our moon will magically be promoted into planethood 30 billion years from now if this definition is accepted. (if the solar system is not destroyed before)

Re: OT: The solar system has 12 planets
 

From the first article linked in the initial post:
"Under the plan, a planet would be any object that orbits a star, is neither a star itself nor the moon of another planet, and contains enough matter that gravity forces it into a nearly round shape."

Er... how much loose dust does it take for it to gravitate into a ball that isn't scattered by the solar wind? Seems like, especially if one goes out to the Kuiper Belt and beyond, there might be many many many of these, and they wouldn't fit an intuitive definition of what a planet is.

Re: OT: The solar system has 12 planets
 

If that's the name they settle on, then most likely in 1000 years when she asks what Xena means the answer will be "It's a planet." Just like these days there aren't too many people that know the mythology behind the other planet names.

Re: OT: The solar system has 12 planets
 

With the proposed addition of Ceres, Pluto or Charon would be #10 http://forum.shrapnelgames.com/images/smilies/happy.gif

Re: OT: The solar system has 12 planets
 

Within 30 billion years, the Sun will long since have gone into its red giant phase, with it's diameter increasing so much as to possibly engluf the Earth and Moon in its outer atmosphere. We won't care where the Earth/Moon barycenter is at that point http://forum.shrapnelgames.com/images/smilies/happy.gif All we'd have left of our Sun is the remnants of a really pretty planetary nebula.

Re: OT: The solar system has 12 planets
 

Very true http://forum.shrapnelgames.com/images/smilies/happy.gif
It's still an akward definition for a planet though, what if Charon had been in an eleptical orbit, so the barycenter would sometimes be inside, and sometimes outside of pluto, would charon change planet-moon status during it's orbit?

The whole double planet thing seems unnecessary, just name the heavier of the two objects the planet and the lighter one the moon, you're unlikely to find two bodies orbiting each other with exactly the same mass. If you do, just dump a couple of tons of material on one of them and your problem is solved. http://forum.shrapnelgames.com/images/smilies/cool.gif

Re: OT: The solar system has 12 planets
 

If I'm understanding the definition of barycenter correctly, a barycenter does not move relative to the objects that define it.

Re: OT: The solar system has 12 planets
 

Hmm the barycentre is indeed defined by the *average* distance between the two objects. Still, if they are in eleptical orbits the distance to the barycentre can change, if I understand correctly, actually it would have to because the objects move closer to each other, so one or both of them have to get closer to the barycentre. the wiki page on 'center of mass'( http://en.wikipedia.org/wiki/Center_of_mass )has an animation of two objects orbiting around their barycentre in an eleptical orbit when you scroll down a bit. in this animation the distance between the objects and the barycentre changes. If the radius of one of them had been a bit over twice as large the barycentre would disapear in it for part of each orbit. (I really should do the math, but that scares me a bit actually, I just hope I'm right http://forum.shrapnelgames.com/images/smilies/fear.gif )

Re: OT: The solar system has 12 planets
 

It would seem that the barycenter for two perfectly spherical bodies would never move. But, if either or both were oddly shaped and rotating, then the barycenter could shift somewhat.

I find the definition of a pluton that depends on the object's origin compelling. Otherwise, how to decide according to size or orbit seems abitrary to me. They shouldn't spend too much time arguing over it, as much of the argument is semantic.

Re: OT: The solar system has 12 planets
 

Nah, i have a very cynical take on this. Given the perodic discussion as to whether pluto is a planet or not, and now the discovery of other objects almost as big, the ones pushing for planet status of the planets and ensuring pluto's status, or looking make a name for themselves to find other planets in the solar system, which is more glamorous, finding a large rock or a small planet. From what i remember, if pluto had been found several years later it would most likely not have been classified as a planet.
pluto was found while ppl where looking for a 9th planet that had been mathmatically calculated to exist, when it was found it was for smaller than expected, hence part of the reason to found the everelusive tenth planet. I think that was before they new the exist of the ort cloaud and kiper belt.

Re: OT: The solar system has 12 planets
 

That's the counter-earth. http://forum.shrapnelgames.com/images/smilies/cool.gif

Re: OT: The solar system has 12 planets
 

The first estimates and predictions of Pluto's mass were far too high, I believe due to miscalculations of the mass of Neptune, which in turn affected the calculations of the mass of Pluto. When they thought it was the size of the Earth, it logically was designated a planet, and when the error was discovered it was a little late.

Re: OT: The solar system has 12 planets
 

i didn't remeber the details haven't really kept track of that stuff in any meaning full detail in years. This redefinition of what a planet it sis doesn't surprise me.

Re: OT: The solar system has 12 planets
 

You're right about one thing: Where egos are involved, what's logical will often take a back seat. http://forum.shrapnelgames.com/image...s/rolleyes.gif

Re: OT: The solar system has 12 planets
 

It doesn’t matter how many objects are classified as planets. What real matters are the questions we study.

Teacher:
“Today class we are studding the inter planets and planetary systems. A planetary system is a planet with one or more moons. How many inter planets and planetary systems are there? Nine, right.”

Re: OT: The solar system has 12 planets
 

Why cant it simply be

A planet is a solar body orbiting a star on its own stationary orbit, having some sort of atmosphere (remember, all nine "current" planets are believed to have one)

With a moon being a solar body that orbits a planet

This is how I always understood it growing up, and it makes complete sense to me

I suppose a size classification would make sense

Re: OT: The solar system has 12 planets
 

Pluto doesn't have an atmosphere, so that wouldn't count it either.

Re: OT: The solar system has 12 planets
 

Oh really?
http://pluto.jhuapl.edu/science/ever...tmosphere.html

Basically, my understanding of everything Ive read about Pluto, the atmosphere isnt exactly stable anyway

Re: OT: The solar system has 12 planets
 

Temporary atmospheres don't count. http://forum.shrapnelgames.com/image...ies/tongue.gif The thing disappears when Pluto moves away, and its made from pieces of the surface that sublimate off, so the point still stands I think.

Re: OT: The solar system has 12 planets
 

tbh though, its a theory that the atmosphere will disappear, we dont know for sure
Lets face it, it was "supposed" to have disappeared already

Re: OT: The solar system has 12 planets
 

There's a few reasons why this definition wouldn't work.

1: What do you do when you find a Kuiper Belt or Oort Cloud object the size of, say, Mars? Given current theories and models of solar system formation, it is possible, even likely that such objects exist at extreme distances from the sun. At such distances, there's no way for it to have an atmosphere...yet if it's as large as Mars, why shouldn't it be classified as a planet?

2: This classification does nothing to address the upper range of planetary sizes, those that are approaching sufficient mass to sustain deuterium fusion, at least for a time. Admittedly, the current definition that has been proposed does nothing to define an upper limit on planetary size, but I think they're planning to reveal one at the upcoming IAU conference in Prague. Your definition doesn't address the boundary between brown dwarf stars and extremely large gas giants.

3: It is theoretically possible to have two similarly sized planets orbitting around a common barycenter, both possessing an atmosphere and orbitting in tandem around their parent star. Your definition technically would exclude these as planets, since they do not each have their own stationary orbit around the star, so they'd essentially end up having to be classified each as a moon of the other, which wouldn't make much sense http://forum.shrapnelgames.com/image...ies/tongue.gif

4: Under your definition, would Mercury qualify as a planet? According to wikipedia's entry on Mercury, its atmosphere is described as below:

This brings up the problem of defining what qualifies as an "atmosphere" and brings problems of its own, such as measuring said atmosphere on Kuiper Belt objects that are so far away as to render atmospheric sampling at our current level of technology impossible.

Whew, that ended up longer than planned. Please feel free to refute my arguments, since they probably have gaping holes in them http://forum.shrapnelgames.com/images/smilies/wink.gif

Re: OT: The solar system has 12 planets
 

Orbiting the sun and witin arbitrary% of round.

Re: OT: The solar system has 12 planets
 

This is where I say who the hell cares. Its a semantic debate based on the word "planet." You want more planets in the solar system, then you widen the definition, if you want less then you curtail the scope.

If they ended up defining Pluto as something other than a planet (or they added those other bodies), then all astronomy books produced in America (and possibly in the world) would have to be rewritten. Do you think that will happen? No. So guess what? While the astronomers go around saying there are X planets (and continue to debate it ad nausium), most people in the world and proboably most publishers would proboably continue to say there are only 9 planets, at least for awhile.

In the end who cares. Rather than wasting countless man hours on the debate of how to define the word planet, lets find out once and for all why the moon is made out of cheese and what type of cheese it is, or better yet astronomers should look for the location of heaven so we can send a space shuttle there and visit God. http://forum.shrapnelgames.com/image...ies/tongue.gif

Re: OT: The solar system has 12 planets
 

Is there a reason for the requirement that a planet has to be orbiting a star? What happens if a big round object forms in space away from any stars, but not massive enough to become a star itself. What do we call such an object?

Re: OT: The solar system has 12 planets
 

...Orbiting a sun or within arbitrary% of round?

Re: OT: The solar system has 12 planets
 

Yeah, the books will be rewritten. It wouldn't require much revision, and it'll give the publishers a chance to put out another version, thus forcing those who wish to keep their libraries up to date to buy yet another volume, making the publishers more money.

Of course, that doesn't mean that people and institutions will replace their books, not until they wear out anyways. Mostly it'll be schools that need new books, but they're too damn cheap to upgrade chemistry textbooks that are 30 years old, so this won't make them buy new books http://forum.shrapnelgames.com/image...s/rolleyes.gif

(Yep, my old high-school uses 30 year old chem. textbooks. Sad, really.)

Re: OT: The solar system has 12 planets
 

In the US, schools and students are frequently buying the latest editions... quite an industry...

But 30-year-old chemistry books? Wow! The opposite extreme.

Re: OT: The solar system has 12 planets
 

Maybe we don't want any more brilliant chemists...

Re: OT: The solar system has 12 planets
 

Schools don't buy books... they make students buy books.

Re: OT: The solar system has 12 planets
 

I'm not sure how it works in Ontario, but here in BC, when you're in highschool the schools purchase the books, not the studnets... If you're referring to university's/college's, of course the students have to buy the books.

Re: OT: The solar system has 12 planets
 

Sure, in theory the highschools buy the books...
But have you ever seen a newly purchased text book in highschool?

Re: OT: The solar system has 12 planets
 

Yep, once. My Biology 12 textbook was totally new. Then again, it was a total piece of crap (little story behind that...). Now it's time to go off on a tangent http://forum.shrapnelgames.com/images/smilies/happy.gif

I had Biology 12 in the second semester of my Gr. 12 year. Book was shiny and new, which for our school was a big thing, sadly enough. Anyways, our school (and I presume all others) had a policy that if you trashed the book you had to pay for its replacement at the end of the year. All well and good, except for the fact that they just patched them up and reused them. But that too is beside the point. At the end of the year, my book was in pristine condition, barely a scratch on it. About a month after school was out, the school sends me a bill for the replacement of the book, telling me that when I gave it to them, the covers were ripped off.

Being the kind of person I am, not willing to pay for damage I know I didn't cause, I ignored the bill. Just a couple months ago I started thinking and realized that the school hadn't sent me my diploma yet. Thinking this was just an oversight on their part, I gave them a call and asked what the holdup was. I end up talking to the principal and find out that they have arbitrarily decided to withhold my diploma, since I haven't paid for the fictional damages. I say the book was in great shape when I gave it to them, and the damage must have occurred afterwards. They, of course, don't believe me, but in their oh so gracious manner, decide to give me a deal on the price of replacement; it'd only cost me $50 instead of the $70 they'd wanted before.

Naturally, I told him I wasn't willing to pay anything for damages I didn't incur, but of course, being the prick he is, he didn't really listen to a damn thing I said.

So, after all that rambling, I was wondering; is it legal for a school principal to not send me my property, over damages that they claim I caused (but can't substantiate the claim) over a year ago? I doubt it is, but when I take up this little battle again in the fall, I'd like to know if I have a leg to stand upon when I demand he give me my property, as his actions are (I think) illegal.

Now, you might be saying to yourself it's a minor thing, and really it is. If I felt like it, I could probably get a replacement diploma from the Ministry of Education, but of course I'd have to pay for that too. Mostly though, I'm too stubborn to allow some [censored] on a power trip to get away with screwing me and who knows how many other people out of their rightfully earned property. It just fries me, worse than it probably should. If he doesn't give it to me I think I'll have to just go there in person and get it myself, despite his protestations. http://forum.shrapnelgames.com/images/smilies/evil.gif I think that'd be...most satisfying.

Whooo. If anyone reads all that, I'll be quite surprised! http://forum.shrapnelgames.com/image...ies/tongue.gif

Re: OT: The solar system has 12 planets
 

It would be a minor thing if you were the only student. It would be a more serious thing if for instance, a large number of students were sent a bill for $70, for a fictitious book replacement. One might even suspect foul play and pocket money.

Re: OT: The solar system has 12 planets
 

I'm not a lawyer, so I can't give you legal advice, but...

It perhaps might be a good idea to contact other students in your chemistry class and ask them if they also recieved a bill. Right now, it's your word against his.

Re: OT: The solar system has 12 planets
 

There's still alot of controversy regarding this, a competing proposal has been put forth demoting Pluto to "dwarf planet" status.

http://www.space.com/scienceastronom...t_newprop.html

Re: OT: The solar system has 12 planets
 

From the previous link:

...the competing proposal, which inserts the criterion that a planet must be 'by far the largest body in its population of bodies'...

To me, this seems like a far worse proposal than a definition based upon gravity. After all, it's extremely ambiguous. They'd first have to define "By far the largest"; how much larger? 50%? 100%? 200? They'd also have to define "Population of bodies". By this would they include all of the Kuiper Belt as being part of the whole Pluto area population? That defines an absolutely massive area. If you're going to include that many cubic light-minutes as an area in which you can only have one planet and it has to be a lot bigger than anything else, then why not include all of the solar system up to Jupiter as being another area? After all, even with that great an area included as a "population of bodies", it would still be a hell of a lot smaller than the entire Kuiper Belt/Oort Cloud region which, it sounds like, this proposal wants to have recognized as being a single "population of bodies". If that were the case, only Jupiter would be a planet! Even it might not make it, since Saturn is relatively close in size. Come to think of it, by the strict application of this definition, you probably wouldn't have ANY planets in the solar system! Nothing could meet the criteria!

Whew. Hope that made sense, though I doubt it did. Even I can barely decipher what I meant to say! http://forum.shrapnelgames.com/image...ies/tongue.gif