Solar System has 8 planets (Pluto demoted)

[Argos]

Originally Posted by haku

No, Xena is a temporary nickname given to the planet by the discoverers, but it won't be the final one, planets must be named after a Greek/Roman deity.

Not quite correct!

Originally Posted by Committee on Small Body Nomenclature

Summary of Guidelines (pre-2003)

* Discoverers have the privilege to propose names for ten years after numbering. Beyond that point, others may propose names.
* Names must be pronounceable, preferably expressible as a single word, and no more than 16 characters in length.
* Individuals or events principally known for political or military activities are unsuitable until 100 years after the death of the individual or the occurrence of the event.
* Names of pet animals are discouraged.
* Minor planets in certain dynamical groups should be named within more restrictive guidelines. For example,
o Trojan asteroids (those that librate in 1:1 resonance with Jupiter) are named for heroes of the Trojan War (Greeks at L4 and Trojans at L5).
o Trans-Jovian planets crossing or approaching the orbit of a giant planet but not in a stabilizing resonance are named for centaurs
o Objects crossing or approaching the orbit of Neptune and in stabilizing resonances other than 1:1 are given mythological names associated with the underworld.
o Objects sufficiently outside Neptune's orbit that orbital stability is reasonably assured for a substantial fraction of the lifetime of the solar system are given mythological names associated with creation.
o Objects that approach or cross Earth's orbit are given mythological names.
* Any decision of the CSBN with which a proposer disagrees may be appealed by the proposer. Since the CSBN now reports to Division III, that appeal should be addressed, by electronic mail or by letter, to the president of Division III, for action by the membership at the following General Assembly.
* The CSBN may choose to act on its own in naming a minor planet and has traditionally done so in each case in which the number is an integral number of thousands.

[Mary-sheccid]

wow°!



xena? the war´s princess? lol! i love it!
a new planet! we go to choose the planet´s name!

i choose MARY!

Is the name of the god´s mother (Jesucristo) i like it? what do your think?

WE PROPOSE OTHERS?

[thegurgi]

I personally think they should name it Vesta or Juno (keeping with the Roman 12 theme, well... other than Saturn and Uranus). Ooo, maybe Juventas

[haku]

Originally Posted by thegurgi

I personally think they should name it Vesta or Juno

Unfortunately those names have already been attributed, here's the official list of all the named objects in the Solar System (except planets and satellites).
One of my favorites has to be Marsupilami, haha.

[mulder]

Xena was indeed used as a code name by the discoverers, who were fans of the show, but they have not submitted it as a proposed name.

Lucy Lawless and Renee O'Connor were both told about the code names back in October 2005 and were thrilled. Lucy's reaction was:

Everytime Sam Raimi hassles my husband, Rob Tapert, about loving making television so much I say, "Aww gee, Sam, is there a planet named Superman? I DON'T THINK SO!!!!" I rang Mike Brown at Cal Tech today to thank him for this senseless act of beauty. Fancy naming a planet and her moon after your characters?! That is just craazy! Renee was at my house yesterday and Sam too and we were all just in disbelief. I had heard 'Xena' was the unofficial name, but didn't dare hope it would stick. God bless us all. That's just CRAAAZY!!!

[haku]

Xena would be accepted as the name of a minor object actually as it's not been used already, but no way the IAU would accept it for a pluton.

There's also a Mr Spock in that list of minor objects, excellent.


I was also reading that astronomers estimate that 53 of the currently known Kuiper Belt objects are big enough to be spherical and therefore granted planet status, and they're expecting to find at least 50 more, so we should get over 100 plutons in the near future.
The more the better actually in my opinion, with a whole lot of plutons, it will be easier to forget about Pluto and Charon which will only become unremarkable objects in a very numerous class of objects, that will only emphasize the remarkable nature of the 8 major planets.
I can see encyclopedias in a few years having sections for each of the 8 major planets, and then a section for the 100 or so plutons.

[mulder]

Yep, from a purely selfish point of view, I would prefer it if the IAU decided there were 8 planets and everything else was not a planet. That way we would get to keep Xena

The winners in all this are going to be book printers. They'll be doing reprints every year to update the latest plutons and raking in the cash from schools and the scientific community

[simon]

Pluto may yet lose its planet status:

http://www.newscientistspace.com/art...et-status.html

I hope the rival motion defeats the official IAU proposal. I don't want to have at least 53 planets by the end of next year. People should accept that calling Pluto a planet in the first place was a mistake, it's just a biggish Kuiper Belt Object.

The whole idea of defining a planet as being round seems particularly absurd to me when 2003EL61 ("Santa"), which is the next largest known KBO after 2003UB313 ("Xena") and Pluto, three-quarters the size of them, is cigar-shaped because it rotates once every four hours. Would 2003EL61 be a planet or not? The IAU won't say, they want to put it on a watch list. Won't it be crazy if they decide it's not a planet, but 43 smaller objects are planets? But if they decide it is a planet, that would make the new 'planets are round' rule a bit meaningless.

Originally Posted by mulder

Yep, from a purely selfish point of view, I would prefer it if the IAU decided there were 8 planets and everything else was not a planet. That way we would get to keep Xena

There's no chance Xena will be the official name. The discoverers have already submitted a name to the IAU, which is awaiting a final decision on 2003UB313's official status. They were told off by the IAU for revealing the name Sedna for an earlier discovery.

[haku]

Originally Posted by simon

Pluto may yet lose its planet status:

http://www.newscientistspace.com/art...et-status.html

That's an interesting counter proposal.

All i'm hoping at this point is that Pluto will be finally put in the right class, either we have 8 planets, or we have 50, but 9 is ridiculous as there's no reason to single out Pluto like that.

[simon]

The IAU is now going to break the two rival proposals down and vote on each part, in an attempt to create a compromise:

http://www.newscientistspace.com/art...finitions.html

The alternative proposal is given here:

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

The alternative proposal still creates a class of 'dwarf planets', but it distinguishes them from planets, which are "by far the largest object in its local population". It doesn't call trans-Neptunian dwarf planets 'plutons' (the word is already used by geologists for something completely different) and it keeps Charon a moon.

The IAU top brass seem to have recognised that the name 'pluton' and making Charon not a moon are very unpopular and I suppose they hope to save Pluto's status as a planet by separating off those aspects of the offiicial proposal.

I hope the alternative proposal is passed, but even the concept of 'dwarf planets' is flawed because whether an object is a spheroid or irregular depends on the material it is made of as well as its size, so smaller objects made of ice can be dwarf planets, but larger and much more massive objects made of rock won't be. See the table in this article:

http://en.wikipedia.org/wiki/Definition_of_planet

[haku]

^ Thanks for the articles.

And LOL, i was not aware that English speakers find the word 'pluton' so ridiculous and laughable… It's how Pluto is called in French

[simon]

Big news! Astronomers are now leaning towards just eight planets:

http://www.newscientistspace.com/art...t-planets.html

Originally Posted by haku

LOL, i was not aware that English speakers find the word 'pluton' so ridiculous and laughable… It's how Pluto is called in French

I thought the main objection was that 'pluton' was a term in geology, rather than that people found the name laughable. There are already 'plutinos' - objects that have a similar orbit to Pluto - and 'cubewanos' - objects in the main Kuiper Belt which unlike Pluto don't have orbits in resonance with Neptune, after the first discovered, 1992QB1. I think cubewano is a slightly ridiculous name. But the latest from Prague is that the names pluton, plutoid, plutonoid and plutid have all been rejected. 'Plutonian object' met with less opposition, which does suggest a preference for formality among the IAU members.

[haku]

Originally Posted by simon

Big news! Astronomers are now leaning towards just eight planets:

http://www.newscientistspace.com/art...t-planets.html

Thanks for the article.

This is pretty exciting news, the new proposal seems fine to me, 8 planets and dwarf planets or planetoids for the other smaller spheroids, i think that works well and is easily understandable by everybody. Hopefully this proposal will pass.
As for creating a special class of Plutonian objects, it seems a bit redundant with Kuiper Belt objects but why not, if this is what it takes to put Pluto where it belongs, it's really not a problem.

[simon]

There's more on what happened at the IAU meeting yesterday in this morning's New York Times (requires regstration):

http://www.nytimes.com/2006/08/23/sc...e/23pluto.html

It seems pretty definite that Pluto is a goner as a planet. The NYT suggests that 'plutonians' is now the favoured name for trans-Neptunian objects. It's less of a mouthful than 'Plutonian objects'. It will be a bit confusing that an object can be a plutonian without being a plutino, but the term KBO is clunky, so plutonian would be better.

Although I was critical of the 'dwarf planet' definition, I think there is a need for an intermediate category, smaller than planets, but bigger than mere asteroids. Pluto used to be the only one, but now there are quite a number. It's also become apparent that Ceres, the biggest asteroid between Mars and Jupiter, is big enough to have some planet-like characteristics (it's spherical and has distinct layers, possibly even a water ocean beneath its surface like Europa and Enceladus) and I agree it should have a distinct status. The difficulty is drawing a boundary that seems consistent in how it treats bodies made of different materials. But Saturn's moon Enceladus shows the problem. It's only 500km across, slightly smaller than Pallas and Vesta, which aren't even properly round, yet it's nothing like the other small objects in the solar system. The body it most resembles is Europa, which is 3000km in diameter, and it has some similarities with Triton and possibly Xena, which are both also much bigger. Some objects act much more grown up than others the same size.

[simon]

The IAU assembly has just finished voting - Pluto is no longer a planet.

They created a new category of dwarf planets including Pluto. Pluto and the other dwarf planets aren't planets - there are just the eight planets out to Neptune. Pluto is the prototype of a new category of trans-Neptunian dwarf planets, but the proposal that they be called 'Plutonian objects' was narrowly defeated. The IAU executive will come up with a new proposal for what to call them.

[mulder]

Pluto has lost it's status as a planet. The IAU has adopted a resolution to retain the 8 classical planets and reclassify Pluto as a dwarf planet.

http://news.bbc.co.uk/1/hi/world/5282440.stm

As all fans have known for years, Xena is a god killer and this proves it

Edit: damn, beaten to it by 2 minutes.

The IAU resolutions and planetary definitions can be found here.

[haku]

Thanks for the great news guys! Wow, considering the proposal we started with last week, i really didn't think we would end up with *less* planets, this is great, i'm very glad Pluto was finally put in the right category.
The creation of a 2-class system with planets and dwarf planets was definitely the best decision, but again, when i read the first IAU proposal last week, i really didn't think that this would be the final results.
This is great! *goes for a drink to celebrate*

[dradeel]

Originally Posted by haku

Wow, considering the proposal we started with last week, i really didn't think we would end up with *less* planets

I was actually guessing this would be the outcome of it. It was honestly the best and easiest solution. And it was something that should've been done from the beginning of

[freddie]

Bah. Too bad. I thought nostalgia would win them over.

Actually one might say now that Mercury is a dwarf planet as well - I'm sure there are many planet like objects in the kuiper's belt which are bigger than Mercury & Pluto combined.

[haku]

Originally Posted by freddie

Actually one might say now that Mercury is a dwarf planet as well - I'm sure there are many planet like objects in the kuiper's belt which are bigger than Mercury & Pluto combined.

Possible, but the planet definition requires that a planet must have cleared its orbit of other objects, and Kuiper Belt objects no matter how big they are have obviously failed to do so since they are part of a *belt*, Mercury on the other hand is alone on its orbit.