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.
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.
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.
> “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).
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?
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.
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".
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.
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.
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.
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.
> 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.
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
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.
> 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?
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.
Like I said: we define it so. Pluto is a planet, the rest aren't. Period.
Yes, there may be some scientific reasons why Pluto isn't a real planet, but considering its history I (and others) believe we should simply overrule that.
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.
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.
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.
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.
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 while looking kind of dim.
> “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.”
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.
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.
"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.
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
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]
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.
...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.
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.
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+.
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.
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.
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.
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.
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).
- 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.
I believe someone was trying to make a name for themselves here and ignoring the history of Pluto and its discovery.
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.
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.
Yes, there may be some scientific reasons why Pluto isn't a real planet, but considering its history I (and others) believe we should simply overrule that.
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.
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.
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.
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 while looking kind of dim.
So… planet Ganymede when? Or Titan?
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!
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.
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.
- 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+.
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