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Planktonne 1 hours ago [-]
The actual problem here is weirdly aggressive nerds who are incapable of nuance, and insist that an astronomical classification (Pluto is not a planet by the IAU definition) should be used in non-astronomical contexts.
Historically and culturally, Pluto is considered a planet. An IAU classification shouldn't be used to try and retroactively change that, because the IAU does not have control over history and culture. It's a fun fact (did you know that Pluto is not classified as a planet by astronomers?) not a diktat.
Similarly, a banana is 'officially' a berry, which means that it is classified as a berry by botanists. This does not mean it is considered a berry in any other contexts. If you told someone you had made a berry crumble and it was filled with bananas, you would look strange. We have countless examples of this (often focused around food): a tomato does not belong in a fruit salad no matter what botanists say.
Different terms are used with different specificity in different settings. Language and culture and [older disciplines] are not governed by the rules of [newer disciplines or bodies]. If people with 'I love space' t-shirts would stop "um actually"-ing, no one would have a problem.
zdragnar 51 minutes ago [-]
Peanuts, cashews, almonds, walnuts, pecans, Brazil nuts and pistachios are culinary nuts but NOT botanical nuts.
Botanical berries: Bananas, tomatoes, grapes, cucumbers, eggplants, avocados and peppers, but NOT strawberries, raspberries, blackberries or mulberries.
Scientists really should have made up their own categories instead of using our words.
odyssey7 15 minutes ago [-]
Well, the thing is, nobody got told, out of nowhere, that the “honorable strawberries” were now called simply “mildly honored straw,” because a committee of so-called experts had expressed their will, and that now everybody had to say “mildly honored straw” instead of “honorable strawberries,” or else they would be *incorrect*, because the science league said so.
The word “planet” signifying a certain reverence, and the fact that a scientific body was now policing everyday language — for the apparently petty reason that we should not honor Pluto as we once did — it was quite a misstep for how people in the public might view science going forward. Unless, perhaps, the idea was to make people more skeptical of scientific results and statements.
bryanlarsen 7 minutes ago [-]
The alternative was to announce "we now have 10 more planets, and there are probably a bunch more, and we'll probably never really get a definitive number".
That would also have had an impact on the public view of science. Perhaps not as bad, but it would have had an impact.
zdragnar 2 minutes ago [-]
No, the alternative would be to make up some latin sounding words for planets, dwarf planets, etc. and leave the vulgar planet alone to the standard 9 that we all know are planets.
odyssey7 4 minutes ago [-]
Planets predate modern astronomy. You have to negotiate with the public if you want to change what “planet” means. To most people, in most contexts, it means 8 or 9 specific things that they have specific ideas about, not a theoretical category of infinite objects.
ketzu 51 minutes ago [-]
I wonder how happy each group would be by this solution. Planet as a scientific and non-scientific usage.
Conclusively, science class would not teach Pluto as a planet (it should after all stick to the science) and English class will discuss the cultural impact of planet Pluto! Maybe write poems about the importance and impact of 9 word mnemonics? Sounds fun.
My headcanon is that people would hate it so so much! I can't wait to see that as a distant observer.
odyssey7 38 minutes ago [-]
This would be a really good discussion topic in schools.
People need to understand the dynamic between science and society, because that is an important part of how the world works today.
Pluto is an exemplar.
And also, the value of culture. It might not be a scientific result, but it still shapes our experience of the world. Pluto is beloved.
odyssey7 48 minutes ago [-]
You’ve explained something very well that I hope certain groups of people will try to internalize.
adrian_b 1 hours ago [-]
> “One of the biggest flaws with the IAU definition is that you can have the same object in two different orbits,” says Kornfeld. “In one, it’s considered a planet, and in the other, it’s not considered a planet.”
No, there is no flaw in this, and moreover there is nothing new in this. This is how it has always been, it is not something invented recently.
In the Solar System, there are 3 Mercury-sized satellites and other 3 Moon-sized satellites, besides the Moon. If they had not been in their orbits as satellites, they might have very well been planets. Therefore the old definition of "planet" also depended on the orbit of the body, not only on the size and shape of the body.
Most of those satellites are bigger than Pluto. Triton, the biggest satellite of Neptune, had been in the distant past another planet with an orbit close to Pluto, but it was captured by Neptune and it has become a satellite. Otherwise it would have remained a "dwarf planet", orbiting close to Pluto. So Triton was demoted from "planet" to "satellite", by Nature, not by a human organization.
The current definition of "planets" and "dwarf planets" is fine.
If anything, there are too few planet classes, not too many. A more useful classification is into big planets, medium planets and small or dwarf planets, where the Solar system has 4 big planets, 4 medium planets, and a lot of small planets.
The big planets, i.e. which are big enough to retain the volatile chemical elements, like hydrogen and noble gases, not only the refractory elements, have a very different chemical composition from the medium planets, and this difference will also exist in any other stellar system that has condensed from gases like those at the origin of the Solar System, with more oxygen than carbon (there exists the possibility of stellar systems with a different chemical composition than the Solar System, formed by condensing from gas mixtures with more carbon than oxygen).
pdonis 25 minutes ago [-]
Since the Moon's orbit is always concave towards the Sun, one could even argue that the Moon is a planet, not a satellite, it just happens to have an orbit that is closely coupled to that of another planet, Earth.
As I understand it, in fact, there was discussion about defining systems like Earth-Moon as double planets, but that didn't make it into the final definition.
ivan_gammel 1 hours ago [-]
I‘m seeing this classification for the first time, but it sounds very reasonable and feels like it should have been like that. Is it your idea or is there any story behind it?
andrewflnr 47 minutes ago [-]
We already have the terms "rocky planet" and "gas giant" that pretty much cover it. The only thing missing is an official IAU decision which, well, would have even less effect than the Pluto thing I'm guessing, since it would just be introducing a sub-division in the category.
ivan_gammel 30 minutes ago [-]
Oh, right. It does exist, it is very accurate, but the names sound like LOTR party:
- a gang of dwarfs
- some rocky ones
- and gas giants
- and one star to rule them all
adrian_b 1 hours ago [-]
Many people use it, but it is not something codified formally by an international organization, like in the IAU definitions of "planet" and "dwarf planet".
jerf 1 hours ago [-]
You know, this is really just a fantastic opportunity to realize the phenomenal psychological power of "headcanon". Who cares if Pluto is or is not tagged with the word "planet" by some organization you know effectively nothing about, have no control over, has no control over you, and couldn't so much as move a pebble on the planetary body in question any time in the next 20 years, if not more?
Have whatever emotional relationship you like with "Pluto" and don't wait around for others to validate it. It's fine. Nobody can stop you. I'm a bit fond of Ceres myself. Nobody can stop me. Nobody needs to approve it. Take control. Write your own headcanon.
1 hours ago [-]
58 minutes ago [-]
drxzcl 1 hours ago [-]
> “One of the biggest flaws with the IAU definition is that you can have the same object in two different orbits,” says Kornfeld. “In one, it’s considered a planet, and in the other, it’s not considered a planet.”
So… planet Ganymede when? Or Titan?
hn_submit 1 hours ago [-]
I'm in the same camp. I believe the classification of Pluto as a dwarf planet was arbitrary and inconsistent. I mean, it's been known as a planet for almost 80 years and suddenly we demote it?
I believe someone was trying to make a name for themselves here and ignoring the history of Pluto and its discovery.
space_fountain 1 hours ago [-]
The issue is that when we discovered Pluto we thought it was much bigger than it turned out to be. If it was as big as they thought then sure it would be a planet. As it is it isn’t even the most massive dwarf planet
hn_submit 58 minutes ago [-]
They saw a problem with the discovery of other Kuiper Belt Objects and came up with a pseudo-scientific definition to "solve" the discrepancy.
vova_hn2 35 minutes ago [-]
> pseudo-scientific definition
How is it pseudo-scientific?
Avshalom 1 hours ago [-]
I'm on team Pluto here but no, the problem was that Mike Brown found like a dozen 'planets' and no one wanted to deal with that. It was closer to preventing someone from making a name for themselves.
hn_submit 55 minutes ago [-]
We could simply define Pluto as the edge of our Solar System and everything beyond its orbit a Kuiper Belt Object. There's nothing wrong with that.
Why bother coming up with a pseudo-scientific requirements list for planets when these don't work for a large number of cases.
vova_hn2 32 minutes ago [-]
> We could simply define Pluto as the edge of our Solar System and everything beyond its orbit a Kuiper Belt Object.
A Kuiper Belt Object not being a part of Solar System doesn't make any sense. A star system is the star + all objects that orbit it. Why would you arbitrarily exclude some objects that orbit the Sun?
bryanlarsen 49 minutes ago [-]
That would include Ceres, Quaoar and Orcus as planets.
It's really hard to come up with a definition of a planet that includes Pluto but doesn't include Orcus. Orcus is very close to a mirror of Pluto that is 120 degrees out of phase. Even in name: Orcus is the Roman name for the Greek god Pluto.
hn_submit 29 minutes ago [-]
What part of "we define it so" did you not understand?!
bryanlarsen 12 minutes ago [-]
The three I listed are inside Pluto's orbit. Part of the time for the latter 2.
If you want to say that Pluto is a planet for historical reasons, that's fine. Just don't try to invent pseudo-scientific nonsense to justify it at the same time you are decrying psuedo-scientific nonsense.
odyssey7 31 minutes ago [-]
> someone was trying to make a name for themselves
100%
Scientists try to coin new terms all the time. It’s great for the researcher if people actually use it. But why do that when you can just sign your name on a term everyone already uses?
Redefining “planet,” from the 9 culturally accepted symbols into something else, was a swindle. “Things that clear their orbits” could have been TTCTOs. It happens all the time, coining precise terms for things. Why should this one have been any different? The public was right to push back and to protect their mythology from the unwelcome incursion.
cobbzilla 58 minutes ago [-]
It was fine and dandy until Eris came along.
Eris is bigger than Pluto, so if Pluto’s a planet then so is Eris. So you have 10 planets.
And then how many other Erises are still hiding? How many planets do we have then? It must be some very large unknown number!
Holding the true number of planets to be a large unknown number was anathema to many.
The demotion of Pluto was primarily motivated by a desire for the word “planet” to refer fixed, never-changing number of large bodies orbiting the sun.
nemomarx 1 hours ago [-]
How to keep Pluto as a planet but say larger objects than it that also orbit the sun aren't planets, is the question I guess?
elictronic 1 hours ago [-]
Literally say Pluto is a planet through the collective statements of parties involved.
This is like when English professors gripe about word usage in books. That's wrong, you can't do that. Then society at large does it and it becomes correct usage. We define our world.
hn_submit 1 hours ago [-]
It's basically a question of definition: we define Pluto as a planet and the others as Kuiper Belt Objects (KBO)
As human beings we're allowed to make these kind of decisions. We define ourselves to be outside of the animal kingdom when we're clearly part of it and a type of animal ourselves.
wolrah 50 minutes ago [-]
The question would be what are the specific rules that lead to that, and how you'd apply those rules outside of our own solar system. Any rule that just calls those distant objects KBOs is specific to our own solar system which is a silly rule to be making in a world where we already knew about hundreds of exoplanets.
The question at hand is "how do we define a planet" from a universal standpoint, because it hadn't really been defined beyond an "I know it when I see it" level and that was becoming a problem.
Objective rules that do not assume you're talking about our solar system are key here, and the serious proposals basically come down to 8 planets or dozens and growing, and from a practical standpoint the former was the obvious choice IMO since all it really affects is what gets focused on in general education environments.
If you just want to make an arbitrary decision that these things are planets because you want them to be as opposed to because they meet certain criteria, that's not useful to anyone.
tanseydavid 1 hours ago [-]
My Very Educated Mother Just Served Us Nine...uhhhm... !?
andrewflnr 55 minutes ago [-]
Nachos. She served us nachos.
chuckadams 56 minutes ago [-]
Mary's Violet Eyes Make John Stay Up Nights.
still works, how bout that?
jsbisviewtiful 1 hours ago [-]
In case anyone was curious, the Moon is bigger than Pluto. Pluto's 2/3 the size of the Moon. If any dwarf planet should be upgraded to a planet, it's Eris. Eris's diameter is over 600km bigger than Pluto's.
lenerdenator 59 minutes ago [-]
Aye, but what does Pluto orbit, and what does the Moon orbit?
vova_hn2 36 minutes ago [-]
Pluto orbits center of combined masses of itself and Charon, which does not lie within either of them. Also, they are both tidally locked to each other, just like Moon is tidally locked to Earth.
ecliptik 53 minutes ago [-]
It's dumb, but whenever I see something representing the planets, I always count them. Occasionally you come across places that still include Pluto.
Most recent example I found was the Swatch MoonSwatch Collection [1], which includes the Sun, Moon, eight planets and Pluto[2].
The problem is that the word “planet” refers both to cultural symbols — mythology, gods, archetypes, and the heavens — and to objects of scientific study. Those are different domains, and one of them is cultural heritage, and the other is irritating when it tries to infringe on the first one.
There’s no need for a god complex. Stop picking and choosing which planets are real. Scientists can create their own, more precise words for things. Planets are sacred. Things that clear their orbits are not.
You can’t subdue the public into giving up their gods out of difference to science — you’re just losing people.
delichon 1 hours ago [-]
I can solve this! What is incompatible with being both a dwarf planet and a major planet? Peter Dinklage is both a dwarf actor and a major actor. Just acknowledge that Pluto is both too. You're welcome.
bryanlarsen 1 hours ago [-]
The main objection to calling Pluto a planet appears to be that if Pluto is a planet then up to about 200 other objects should also be called planets, that the list would be of unknown size and regularly changing.
That's an objection? No, that's a benefit! I think it'd be awesome to be regularly discovering new planets.
andrewflnr 59 minutes ago [-]
"Discovering new planets" only has the cachet it does because there are so few of them, and they are individually so significant. It would quickly lose that significance if there were hundreds of them. To be precise, it would acquire exactly the significance it actually deserves, but having diluted the meaning of "planet" as applied to the big eight in the process. We would soon want another name for the originals to compensate.
We can still be reasonably excited about discovering new things in the solar system without pretending they're in the same category as Earth and Neptune.
Sharlin 1 hours ago [-]
This seems like the least important issue in the world to keep complaining about.
KineticLensman 2 hours ago [-]
"How I Killed Pluto and Why It Had It Coming" - awesome title for an Astronomy book
drxzcl 2 hours ago [-]
It’s not exactly an astronomy book. It’s more a memoir of an astronomer. But it’s funny and very well written.
Also, if you have the opportunity too see @plutokiller teach planetary science or give a lecture, I can recommend you do so!
Oarch 1 hours ago [-]
Back in school I learned the acronym:
My
Very
Easy
Method
Just
Speeds
Up
Naming
Planets
And it was so convenient! Does anyone know a good alternate now that the P is gone?
petcat 1 hours ago [-]
> Does anyone know a good alternate now that the P is gone?
My Very Easy Method Just Speeds Up Naming
tehnoslow 56 minutes ago [-]
The claim that the IAU vote was procedurally invalid is interesting
kazinator 1 hours ago [-]
> Pluto represents the underdog ...
I see what Schindler did there!
GrumpySciGuy 59 minutes ago [-]
Let the experts decide same with any other field.
animitronix 58 minutes ago [-]
It's time to give it up. Nobody wants there to be 23 planets...
adolph 1 hours ago [-]
It seems as though Pluto's primary problem is "clearing the neighbourhood." Given Pluto's orbit travels closer and further from the sun than Neptune, does Neptune also have the neighborhood clearing problem since it has not cleared Pluto?
In celestial mechanics, "clearing the neighbourhood" (or dynamical dominance)
around a celestial body's orbit describes the body becoming gravitationally
dominant such that there are no other bodies of comparable size other than
its natural satellites or those otherwise under its gravitational influence.[0]
Trans-neptunian objects, including Pluto, are in orbital resonance. They owe their stable orbits to the existence of Neptune.
It’s like saying Jupiter is not a planet because the Trojans exist.
beloch 1 hours ago [-]
...or like saying Earth is not a planet because NEA's share our orbit.
If you have to argue that it doesn't apply to Jupiter or Earth because they are obviously planets, it implies that "clearing the neighbourhood" is a vague and not particularly useful criteria.
drxzcl 59 minutes ago [-]
Except I said nothing of the sort. I said the opposite.
Jupiter, Neptune and earth in your example dominate the gravity of their orbit by locking the smaller bodies into orbital reasonances.
It’s not a vague criterium. It might be an irrelevant one if you are interested in geophysics, but it’s concrete and testable.
46 minutes ago [-]
vova_hn2 48 minutes ago [-]
> other bodies of comparable size
In addition to what other commenters said about orbital resonance: Neptune has approximately 20 times bigger radius and is about 10_000 (ten thousand) times heavier. This is comparable to difference in mass between a human and a hummingbird. Could we really call them "comparable size"? I'm not sure, this is not a particularly precise term, but I would say - no.
andrewflnr 1 hours ago [-]
The "Criteria" section of that article clarifies the question. Neptune holds Pluto in an orbital resonance, which qualifies as Neptune gravitationally dominating its neighborhood. Perfect, 100% clearance is not expected anyway, since that's basically impossible in a real, dirty world where things move around.
metalman 55 minutes ago [-]
Pluto as one of the outer Canadian planets in the Canadian solar system, which as you now know is part of the Canadian Galaxy is realy such a trifling concern back on one of the Canadian Continents that contains Canada proper the center of Universal Canada, but since there is dissent on it's status something can be done through a referendum.
go ahead,laugh, but wait till google AND wikipedia both come on board
baggy_trough 56 minutes ago [-]
The correct planet criteria are, IMHO:
- not a star
- not orbiting a planet
- roundish
- greater than 1000km radius
That would restore Pluto to its rightful place and add Eris.
baggy_trough 2 hours ago [-]
Bring back Pluto!
gus_massa 1 hours ago [-]
As the article explains, if you bring back Pluto you must include Eris too, and perhaps Makemake and Haumea if you ignore is not as round as expected, and who know how many other undiscovered small object near them. (And Ceres? I like Ceres.)
Anyway, 9 is not an option, you must choose 8 or 10+.
flerchin 1 hours ago [-]
I'm on board with all the dwarf planets. MVEMCJSUNPHME should be easy to make a mnemonic.
elictronic 1 hours ago [-]
Pluto is grandfathered in through the collective Consciousness of society. Just treat it the same way as tomatoes, which are officially fruits but no child believes that crap.
gus_massa 15 minutes ago [-]
My daughter heard that tomatoes are fruit in YouTube, and now she wants to reclassify pumpkins and half of the vegetable as fruits.
Next time you go to the grocery, grab a cucumber and a watermelon and try to find the differences.
snapcaster 1 hours ago [-]
no you don't. just because some nerds say it doesn't make it true. just bring back pluto and nothing else
wolrah 1 hours ago [-]
Science works on logical rules.
What logical rule would you propose that allows Pluto to be a planet without also bringing in a bunch of others?
If you just want to arbitrarily declare things are they way you like them to be, religion is over there.
snapcaster 33 minutes ago [-]
>What logical rule would you propose that allows Pluto to be a planet without also bringing in a bunch of others?
The rule would be: pluto is a planet, stay mad nerds
drxzcl 2 hours ago [-]
It’s still there. Where it always was.
heyitsmedotjayb 2 hours ago [-]
It's been renamed to Planet America, thank you for your attention on this matter.
Historically and culturally, Pluto is considered a planet. An IAU classification shouldn't be used to try and retroactively change that, because the IAU does not have control over history and culture. It's a fun fact (did you know that Pluto is not classified as a planet by astronomers?) not a diktat.
Similarly, a banana is 'officially' a berry, which means that it is classified as a berry by botanists. This does not mean it is considered a berry in any other contexts. If you told someone you had made a berry crumble and it was filled with bananas, you would look strange. We have countless examples of this (often focused around food): a tomato does not belong in a fruit salad no matter what botanists say.
Different terms are used with different specificity in different settings. Language and culture and [older disciplines] are not governed by the rules of [newer disciplines or bodies]. If people with 'I love space' t-shirts would stop "um actually"-ing, no one would have a problem.
Botanical berries: Bananas, tomatoes, grapes, cucumbers, eggplants, avocados and peppers, but NOT strawberries, raspberries, blackberries or mulberries.
Scientists really should have made up their own categories instead of using our words.
The word “planet” signifying a certain reverence, and the fact that a scientific body was now policing everyday language — for the apparently petty reason that we should not honor Pluto as we once did — it was quite a misstep for how people in the public might view science going forward. Unless, perhaps, the idea was to make people more skeptical of scientific results and statements.
That would also have had an impact on the public view of science. Perhaps not as bad, but it would have had an impact.
Conclusively, science class would not teach Pluto as a planet (it should after all stick to the science) and English class will discuss the cultural impact of planet Pluto! Maybe write poems about the importance and impact of 9 word mnemonics? Sounds fun.
My headcanon is that people would hate it so so much! I can't wait to see that as a distant observer.
People need to understand the dynamic between science and society, because that is an important part of how the world works today.
Pluto is an exemplar.
And also, the value of culture. It might not be a scientific result, but it still shapes our experience of the world. Pluto is beloved.
No, there is no flaw in this, and moreover there is nothing new in this. This is how it has always been, it is not something invented recently.
In the Solar System, there are 3 Mercury-sized satellites and other 3 Moon-sized satellites, besides the Moon. If they had not been in their orbits as satellites, they might have very well been planets. Therefore the old definition of "planet" also depended on the orbit of the body, not only on the size and shape of the body.
Most of those satellites are bigger than Pluto. Triton, the biggest satellite of Neptune, had been in the distant past another planet with an orbit close to Pluto, but it was captured by Neptune and it has become a satellite. Otherwise it would have remained a "dwarf planet", orbiting close to Pluto. So Triton was demoted from "planet" to "satellite", by Nature, not by a human organization.
The current definition of "planets" and "dwarf planets" is fine.
If anything, there are too few planet classes, not too many. A more useful classification is into big planets, medium planets and small or dwarf planets, where the Solar system has 4 big planets, 4 medium planets, and a lot of small planets.
The big planets, i.e. which are big enough to retain the volatile chemical elements, like hydrogen and noble gases, not only the refractory elements, have a very different chemical composition from the medium planets, and this difference will also exist in any other stellar system that has condensed from gases like those at the origin of the Solar System, with more oxygen than carbon (there exists the possibility of stellar systems with a different chemical composition than the Solar System, formed by condensing from gas mixtures with more carbon than oxygen).
As I understand it, in fact, there was discussion about defining systems like Earth-Moon as double planets, but that didn't make it into the final definition.
- a gang of dwarfs
- some rocky ones
- and gas giants
- and one star to rule them all
Have whatever emotional relationship you like with "Pluto" and don't wait around for others to validate it. It's fine. Nobody can stop you. I'm a bit fond of Ceres myself. Nobody can stop me. Nobody needs to approve it. Take control. Write your own headcanon.
So… planet Ganymede when? Or Titan?
I believe someone was trying to make a name for themselves here and ignoring the history of Pluto and its discovery.
How is it pseudo-scientific?
Why bother coming up with a pseudo-scientific requirements list for planets when these don't work for a large number of cases.
A Kuiper Belt Object not being a part of Solar System doesn't make any sense. A star system is the star + all objects that orbit it. Why would you arbitrarily exclude some objects that orbit the Sun?
It's really hard to come up with a definition of a planet that includes Pluto but doesn't include Orcus. Orcus is very close to a mirror of Pluto that is 120 degrees out of phase. Even in name: Orcus is the Roman name for the Greek god Pluto.
If you want to say that Pluto is a planet for historical reasons, that's fine. Just don't try to invent pseudo-scientific nonsense to justify it at the same time you are decrying psuedo-scientific nonsense.
100%
Scientists try to coin new terms all the time. It’s great for the researcher if people actually use it. But why do that when you can just sign your name on a term everyone already uses?
Redefining “planet,” from the 9 culturally accepted symbols into something else, was a swindle. “Things that clear their orbits” could have been TTCTOs. It happens all the time, coining precise terms for things. Why should this one have been any different? The public was right to push back and to protect their mythology from the unwelcome incursion.
Eris is bigger than Pluto, so if Pluto’s a planet then so is Eris. So you have 10 planets.
And then how many other Erises are still hiding? How many planets do we have then? It must be some very large unknown number!
Holding the true number of planets to be a large unknown number was anathema to many.
The demotion of Pluto was primarily motivated by a desire for the word “planet” to refer fixed, never-changing number of large bodies orbiting the sun.
This is like when English professors gripe about word usage in books. That's wrong, you can't do that. Then society at large does it and it becomes correct usage. We define our world.
As human beings we're allowed to make these kind of decisions. We define ourselves to be outside of the animal kingdom when we're clearly part of it and a type of animal ourselves.
The question at hand is "how do we define a planet" from a universal standpoint, because it hadn't really been defined beyond an "I know it when I see it" level and that was becoming a problem.
Objective rules that do not assume you're talking about our solar system are key here, and the serious proposals basically come down to 8 planets or dozens and growing, and from a practical standpoint the former was the obvious choice IMO since all it really affects is what gets focused on in general education environments.
If you just want to make an arbitrary decision that these things are planets because you want them to be as opposed to because they meet certain criteria, that's not useful to anyone.
still works, how bout that?
Most recent example I found was the Swatch MoonSwatch Collection [1], which includes the Sun, Moon, eight planets and Pluto[2].
1. https://www.swatch.com/en-us/bioceramic-moonswatch-collectio...
2. https://www.swatch.com/en-us/mission-to-pluto-so33m101/SO33M...
There’s no need for a god complex. Stop picking and choosing which planets are real. Scientists can create their own, more precise words for things. Planets are sacred. Things that clear their orbits are not.
You can’t subdue the public into giving up their gods out of difference to science — you’re just losing people.
That's an objection? No, that's a benefit! I think it'd be awesome to be regularly discovering new planets.
We can still be reasonably excited about discovering new things in the solar system without pretending they're in the same category as Earth and Neptune.
Also, if you have the opportunity too see @plutokiller teach planetary science or give a lecture, I can recommend you do so!
My Very Easy Method Just Speeds Up Naming Planets
And it was so convenient! Does anyone know a good alternate now that the P is gone?
My Very Easy Method Just Speeds Up Naming
I see what Schindler did there!
It’s like saying Jupiter is not a planet because the Trojans exist.
If you have to argue that it doesn't apply to Jupiter or Earth because they are obviously planets, it implies that "clearing the neighbourhood" is a vague and not particularly useful criteria.
Jupiter, Neptune and earth in your example dominate the gravity of their orbit by locking the smaller bodies into orbital reasonances.
It’s not a vague criterium. It might be an irrelevant one if you are interested in geophysics, but it’s concrete and testable.
In addition to what other commenters said about orbital resonance: Neptune has approximately 20 times bigger radius and is about 10_000 (ten thousand) times heavier. This is comparable to difference in mass between a human and a hummingbird. Could we really call them "comparable size"? I'm not sure, this is not a particularly precise term, but I would say - no.
- not a star
- not orbiting a planet
- roundish
- greater than 1000km radius
That would restore Pluto to its rightful place and add Eris.
Anyway, 9 is not an option, you must choose 8 or 10+.
Next time you go to the grocery, grab a cucumber and a watermelon and try to find the differences.
What logical rule would you propose that allows Pluto to be a planet without also bringing in a bunch of others?
If you just want to arbitrarily declare things are they way you like them to be, religion is over there.
The rule would be: pluto is a planet, stay mad nerds