Is Pluto Really Not a Planet Anymore?

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The discussion centers around the controversial demotion of Pluto from planet status to that of a dwarf planet, with participants expressing a mix of humor and frustration. Key points include concerns about Pluto's due process rights in the decision-making process, the implications of classifying celestial bodies, and the potential for a large number of planets if the Kuiper Belt is fully explored. Participants reflect on their childhood perceptions of the solar system, with some advocating for the recognition of Earth's moon as a binary planet alongside Earth. The conversation also touches on the definitions of "dwarf planet," with some arguing that the terminology is misleading. The discovery of Eris is noted as a significant factor in the reclassification of Pluto, leading to broader discussions about the criteria for planetary status and the nature of celestial classification. Overall, the thread blends scientific inquiry with lighthearted banter about the implications of these astronomical definitions.
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What do you think about the decision?
 
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Well, Pluto wasn't provided with a lawyer, so I think they violated his due process rights.
 
That's true
 
Pluto was pissed. It tried to leave the solar system but conservation of energy got its revenge.
 
This is ridiculous. How can a dog be a planet.
 
Dremmer said:
What do you think about the decision?
Serious answer:

It reminds me of when I learned that dinosaurs were more like birds and not reptiles. Or that Santa Claus doesn't exist.

The dinosaurs didn't change from reptiles into birds, and Santa Claus was never a real person who just stopped existing one day. Instead, I just got access to better information. That's how I feel about Pluto.
 
Dremmer said:
What do you think about the decision?

Well, we either have 8 planets in our solar system, or we have something like 20-30+ planets (once the Kuiper Belt is better explored) in our solar system. I'd rather stick with just the 8 major planets, and then various dwarf planets.
 
There were 4 asteroids that used to be considered planets. They got kicked out of the limosine in much the same way as Pluto did.

wiki said:
Ceres was assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno and 4 Vesta) for about half a century

http://en.wikipedia.org/wiki/Ceres_(dwarf_planet)"
 
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Dremmer said:
What do you think about the decision?

One important fact is that Pluto has a substantial satellite with even larger diameter than Ceres mentioned above. But, I guess tough little brothers don't help elevate one's status these days.

In some ways own moon is a better example of a planet than Pluto. It's almost twice the diameter; and, as part of the binary earth/moon system, it orbits the sun as a proper planet should, unlike Pluto.

As someone who grew up thinking we had 9 planets, I do have to say that I'm a little ticked off. I hope for our Moon to eventually be officially recognized as our ninth planet for the simple reason that when I get old and senile and revert back to saying there are 9 planets, the children won't realize that I've lost my mind.

(And yes I know that Titan, Triton and the 4 main Jupitor moons are at similar or even larger size to our moon, but the Earth/Moon system is the only possible candidate for a binary planet in our solar system. Well, I guess Pluto/Charon might have qualified, but that's not an option now. :smile: )
 
  • #10
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  • #11
Perhaps Pluto should consider paying its taxes to the Solar Revenue System.
 
  • #12
Jack21222 said:
Well, we either have 8 planets in our solar system, or we have something like 20-30+ planets (once the Kuiper Belt is better explored) in our solar system. I'd rather stick with just the 8 major planets, and then various dwarf planets.

And minor planets -- thousands of those. http://www.cfa.harvard.edu/iau/lists/MPDiscsNum.html"

I was sore about Pluto not being a planet when it happened, but I learned why and I've accepted it *wipes tear* Does anyone have a tissue?
 
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  • #13
russ_watters said:
Well, Pluto wasn't provided with a lawyer, so I think they violated his due process rights.
I've heard the ACLU has decided to create a media blitz and take up Pluto's cause.
 
  • #14
Everyone bemoans the deflated status of pluto.

I think we should make a positive spin on this instead:
Charon isn't classafied as a moon any longer, it is upgraded to dwarf planet status! :smile:
 
  • #15
Evo said:
I've heard the ACLU has decided to create a media blitz and take up Pluto's cause.

I knew it! Pluto is a commie planet!

Pluto, if the orbit don't fit, you must acquit!
 
  • #16
arildno said:
Charon isn't classafied as a moon any longer, it is upgraded to dwarf planet status! :smile:
Really? *googles it*
I have to admit I am quite fond of Sedna :) And Haumea's pretty interesting too :biggrin:
 
  • #17
I thought it was because Earth's moon was jealous saying "If Pluto is a planet, I want to be a Planet too."
 
  • #18
I like Neil deGrasse Tyson's take on it. Pluto wasn't demoted... it was a promotion! It is no longer the smallest, most insignificant planet... it's now King of the Kuiper Belt!
 
  • #19
Jack21222 said:
It is no longer the smallest, most insignificant planet... it's now King of the Kuiper Belt!

Now its name has even more meaning! Pluto, as God of the Underworld, would "rather rule in hell than serve in heaven".
 
  • #20
I have some problems with the new definition, but probably not for the same reasons most people do.

Firstly, calling it a dwarf planet implies to most people that it's still a planet, just a dwarf one. It's not, it's not a planet which is dwarf, but a dwarf planet. In this case, dwarf is a noun not an adjective. That's confusing and could have been avoided.

Also, one factor in considering something as a planet is that it should have cleared it's orbit. Well, if you want to get technical, none of the planets have entirely cleared their orbits. It might have been better if it had been something like "must be the dominant body in it's orbit". Well, something like that, anyways.

I'm not upset over Pluto's demotion. It had it comin' to it. But the definition leaves much to be desired, IMO.
 
  • #21
skeptic2 said:
I thought it was because Earth's moon was jealous saying "If Pluto is a planet, I want to be a Planet too."

It will be nice to consider Earth/Moon system as a binary planet system.
 
  • #22
I think the discovery of Eris was a major deciding factor in the decision to define "dwarf planets." Eris is estimated 27% more massive than Pluto, so if Pluto was a planet Eris would have to be one too...

Wikipedia.org said:
Eris ... is the most massive known dwarf planet in the Solar System and the ninth most massive body known to orbit the Sun directly. It is estimated to be approximately 2300–2400 km in diameter, and 27% more massive than Pluto or about 0.27% of the Earth's mass.
...
Eris has one moon, Dysnomia. As of 2010, its distance from the Sun is 96.6 AU, roughly three times that of Pluto. With the exception of some comets the pair are currently the most distant known natural objects in the Solar System.
...
[Eris' discovery], along with the prospect of other similarly sized objects being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under a then-new IAU definition approved on August 24, 2006, Eris is a "dwarf planet" along with Pluto, Ceres, Haumea and Makemake.

http://en.wikipedia.org/wiki/Eris_(dwarf_planet )
 
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  • #23
Grep said:
Firstly, calling it a dwarf planet implies to most people that it's still a planet, just a dwarf one. It's not, it's not a planet which is dwarf, but a dwarf planet. In this case, dwarf is a noun not an adjective. That's confusing and could have been avoided.

Umm... if "dwarf" is the noun, then planet is the adjective? I guess that would mean it should be "planetary." A dwarf planetary? Doesn't roll of the tongue.

Actually, it could be like "court martial" in which case the "martial" is a postpositive describing the noun. If that's the case, then the plural of "dwarf planet" is actually "dwarves planet."
  • Courts Martial
  • Attornies General
  • Leaves of Absence
  • Dwarves Planet

I just don't know, man...
 
  • #24
Upisoft said:
It will be nice to consider Earth/Moon system as a binary planet system.

I agree, but we have to wait a couple of billion years before it will happen. In a classic case of arbitrary definitions, a binary planet must have its center of gravity outside the larger body. Right now, the CG radius of Earth/Moon system is at about 75% of the Earth radius. However, the distance between the Earth and the moon is gradually increasing and I project that before our sun goes nova the earth/moon system will classify as a binary planet.

I feel the definition should be changed to suit my own selfish needs. Four possible definitions would work here.

1. The CG distance must be more than half of the larger planet radius.

2. The CG must be more than the SMALLER planet radius.

3. The CG must be more than the average of both planet radii.

4. The CG must be projected to be greater than the larger radius before the sun goes nova.

I know I'm stretching here for a pointless classification, but I really want my 9th planet back. I'm not picky, any planet will do, but our Moon seems to be my only chance. :smile:
 
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  • #25
FlexGunship said:
Umm... if "dwarf" is the noun, then planet is the adjective? I guess that would mean it should be "planetary." A dwarf planetary? Doesn't roll of the tongue
It does not indeed. However, both "dwarf" and "planet" are nouns, in this case. :smile:
 
  • #26
Grep said:
Firstly, calling it a dwarf planet implies to most people that it's still a planet, just a dwarf one. It's not, it's not a planet which is dwarf, but a dwarf planet. In this case, dwarf is a noun not an adjective. That's confusing and could have been avoided.
That argument is a bit of a red herring. Consider that
  • Cartesian tensors are not tensors. (Not all cartesian tensors are tensors, and not all tensors are cartesian tensors.)
  • The metric tensor in general relativity is not a metric. (The metric tensor in GR is not positive definite.)
  • Most amazing of all, red herrings are typically neither red nor herrings.
 
  • #27
FlexGunship said:
Umm... if "dwarf" is the noun, then planet is the adjective? I guess that would mean it should be "planetary." A dwarf planetary? Doesn't roll of the tongue.

Actually, it could be like "court martial" in which case the "martial" is a postpositive describing the noun. If that's the case, then the plural of "dwarf planet" is actually "dwarves planet."
  • Courts Martial
  • Attornies General
  • Leaves of Absence
  • Dwarves Planet

I just don't know, man...

Wouldn't it make more sense for the whole phrase "dwarf planet" to be a noun in its own right, as is suggested by the Oxford Dictionary of English? Perhaps this would clearer if it was hyphenated.
 
  • #28
Grep said:
It does not indeed. However, both "dwarf" and "planet" are nouns, in this case. :smile:

Hmm, really? This might bee a grammatical first. Can you cite precedent?

D H said:
Most amazing of all, red herrings are typically neither red nor herrings.

Oh, I strongly beg to differ, sir! The original red herring was, in fact, a red herring (literally, and figuratively). But this seems to be a non-sequitur (still better than being a non-planet).
 
  • #29
Vagn said:
Wouldn't it make more sense for the whole phrase "dwarf planet" to be a noun in its own right, as is suggested by the Oxford Dictionary of English? Perhaps this would clearer if it was hyphenated.

I believe that even http://en.wikipedia.org/wiki/Noun_phrase" are considered to have constituent parts; one of which is a noun. The discussion seems to be centering around whether the "dwarf" or the "planet" is the noun.

EDIT: 50% MORE CONTENT FOR FREE!

One possibility says that "planet" is the noun. In which case you have <adjective><noun>. This is common, like "black coat" and "tall building." Or, like a noun phrase, you could say: "blond girl."

The other possibility is that "dwarf" is the noun. in which case you have <noun><postpositive adjective>. This is less common, but still common enough. Examples are: "court martial", "attorney general" or "coat of arms." In reality, it's a "martial court" and "general attorney" but convention seems to carry this type of flair with it.

Of these two scenarios, the first gives us a plural of "dwarf planets" and the second gives us a plural of "dwarves planetary." In reality, the second would likely be said: "planetary dwarves" just like "general attornies."
 
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  • #30
HeLiXe said:
Really? *googles it*
I have to admit I am quite fond of Sedna :) And Haumea's pretty interesting too :biggrin:

Sedna? Haumea?

Quaoar!

How can you deny a dwarfie named Quaoar?!
 
  • #31
Mech_Engineer said:
I think the discovery of Eris was a major deciding factor in the decision to define "dwarf planets." Eris is estimated 27% more massive than Pluto, so if Pluto was a planet Eris would have to be one too...



http://en.wikipedia.org/wiki/Eris_(dwarf_planet )

hmmm...

so A-E-I-O-U and sometimes Y (and W?)

and M-V-E-M-J-S-U-N and sometimes Pluto (and Eris?)
 
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  • #32
Vagn said:
Wouldn't it make more sense for the whole phrase "dwarf planet" to be a noun in its own right, as is suggested by the Oxford Dictionary of English? Perhaps this would clearer if it was hyphenated.
You're probably right about that. But really, I rest my case. It's not incorrect, I think, just confusing to the general public. I don't like having to explain to people why a dwarf planet is not, in fact, a planet even though the word is right in there. It should be totally unnecessary.

That said, I'm not really losing sleep over it.
 
  • #33
Grep said:
That said, I'm not really losing sleep over it.

Yeah, but now I am! There's a grammatical nightmare afoot.
 
  • #34
FlexGunship said:
Yeah, but now I am! There's a grammatical nightmare afoot.
:bugeye: :smile:
 
  • #35
It's a red herring. Neither red, nor herring.
 
  • #36
Jimmy Snyder said:
It's a red herring. Neither red, nor herring.

Where?! *gets frying pan and oil*
 
  • #37
Chi Meson said:
Sedna? Haumea?

Quaoar!

How can you deny a dwarfie named Quaoar?!

True...but Quaoar only has a cool name, Sedna has a pretty orbit and Haumea is beautifully oval:biggrin:
kuiper.jpg

look at that sexy thing!:-p
 
  • #39
Chi Meson said:
Here's a nice composite of the largest TNOs:
I hadn't realized until now that the Earth is trans-Neptunian.
 
  • #40
HeLiXe said:
kuiper.jpg

look at that sexy thing!:-p

I think I am too old. It doesn't look sexy to me.
 
  • #41
Borek said:
I think I am too old. It doesn't look sexy to me.
You're not too old, you're just spoiled by Marzena.
 
  • #42
Jimmy Snyder said:
I hadn't realized until now that the Earth is trans-Neptunian.

And the largest!
 
  • #43
Borek said:
This is ridiculous. How can a dog be a planet.

Well, if you feed it enough...
 
  • #44
Borek said:
I think I am too old. It doesn't look sexy to me.
Perhaps you're more of a spherical guy?
 
  • #46
HeLiXe said:
True...but Quaoar only has a cool name, Sedna has a pretty orbit and Haumea is beautifully oval:biggrin:
kuiper.jpg

look at that sexy thing!:-p
It looks like an ostrich egg.
 
  • #47
Pluto is no longer a planet?

What's next: you going to tell me that Cruithne is no longer our moon?
 
  • #48
Astronuc said:
It looks like an ostrich egg.
>_> Now what am I supposed to say...if I agree, everyone will think I find ostrich eggs sexy!
Gokul43201 said:
What's next: you going to tell me that Cruithne is no longer our moon?

NO WAY! I never knew about this! Thanks Gokul, this completely blew my mind tonight.
 
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