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Pluto Should Be Reclassified as a Planet, Experts Say (sciencedaily.com)
The reason Pluto lost its planet status is not valid, according to new research from the University of Central Florida in Orlando. From a report: In 2006, the International Astronomical Union, a global group of astronomy experts, established a definition of a planet that required it to "clear" its orbit, or in other words, be the largest gravitational force in its orbit. Since Neptune's gravity influences its neighboring planet Pluto, and Pluto shares its orbit with frozen gases and objects in the Kuiper belt, that meant Pluto was out of planet status. However, in a new study published online Wednesday in the journal Icarus, UCF planetary scientist Philip Metzger, who is with the university's Florida Space Institute, reported that this standard for classifying planets is not supported in the research literature. Metzger, who is lead author on the study, reviewed scientific literature from the past 200 years and found only one publication -- from 1802 -- that used the clearing-orbit requirement to classify planets, and it was based on since-disproven reasoning. He said moons such as Saturn's Titan and Jupiter's Europa have been routinely called planets by planetary scientists since the time of Galileo.
"The IAU definition would say that the fundamental object of planetary science, the planet, is supposed to be a defined on the basis of a concept that nobody uses in their research," Metzger said. "And it would leave out the second-most complex, interesting planet in our solar system." "We now have a list of well over 100 recent examples of planetary scientists using the word planet in a way that violates the IAU definition, but they are doing it because it's functionally useful," he said. "It's a sloppy definition," Metzger said of the IAU's definition. "They didn't say what they meant by clearing their orbit. If you take that literally, then there are no planets, because no planet clears its orbit."
"The IAU definition would say that the fundamental object of planetary science, the planet, is supposed to be a defined on the basis of a concept that nobody uses in their research," Metzger said. "And it would leave out the second-most complex, interesting planet in our solar system." "We now have a list of well over 100 recent examples of planetary scientists using the word planet in a way that violates the IAU definition, but they are doing it because it's functionally useful," he said. "It's a sloppy definition," Metzger said of the IAU's definition. "They didn't say what they meant by clearing their orbit. If you take that literally, then there are no planets, because no planet clears its orbit."
Jerry Smith.
It's so weird to see people get so emotional about this.
I mean, Pluto was called a planet when I was growing up too, but I've moved on.
The redefinition of the phrase presented in the summary is silly. “Clearing its orbit” means just what it says. But then Neptune also fails that test, since it hasn’t “cleared its orbit” of Pluto - and therein lies the problem.
If scientists had meant a planet should “be the largest gravitational force in its orbit”, they would have said exactly that. The phrasing is clear, concise, and unambiguous.
#DeleteChrome
$250 for a new textbook I can see why they flipit
As people who classifying and organizing information is second nature, this is a pretty huge "duh" kind of thing.
Far from removing things from the "planet" group, the higher super-set of "planet" should be all inclusive and loosely defined itself.
Instead there should be sub-sets of different types of planets, like you know, how most of them have been for some time now.
A good naming hierarchy is your friend.
Even the name "dwarf planet" implies a sub-type of "planet" called "dwarf"
Keep splitting up groups into smaller groups that have more detailed distinctions as our knowledge increases.
Even the current useless definition of stupid can fit inside such a classification system without messing with the actual scientifically defined distinctions already used.
I for one wouldn't want to see kids in school forced to learn "names of planets in our solar system" coming from a list with millions upon millions of names in it, which is why inside vs outside of the kuiper belt is one great distinction.
But this just means two new group names to represent inside vs outside of that belt, and you learn the list of whatever we name that inside the belt group.
But despite where or how far a planet is, it should still be a planet.
Reclassify? But Pluto has always been a planet and shall also be in the future. Why, are some poor misguided souls saying otherwise?
What's a planet?
You're right. It doesn't matter whether or not we classify it as a planet, but Disney, Inc. had better step up and make sure that we stop calling it Pluto.
We don't consider medical definitions in the context of the four humours, heck late 19th century astronomers thought space was filled with luminiferous aether so why are their opinions on the definition of planets suddenly considered insightful.
So how many planets do you want?
If we let Pluto be a planet, then our solar system will also have to start officially calling all the other minor planets, planets. i don't think that's reasonable or important. its simply not worth it. Pluto is a an object, we know its there, but it doesn't need to be on a list that includes the 8 major planets. i don't care how you categorize it, we simply cannot have a never ending list of planets to include in our definition of the solar system.
-Jeff
Impacts on Earth and Jupiter clearly show they haven't "Cleared their Orbits" either.
Read the Wikipedia article on clearing the neighborhood. It's defined well enough and people know what it means. Claiming that "If you take that literally, then there are no planets, because no planet clears its orbit." is like pointing to the requirement that a planet must be round, and saying that if you take that literally, no planet is round. Yes, no planet is 100% round, but it's possible for a planet to be close to round or not very close to round, and the same goes for clearing the neighborhood.
The research that shows that nobody used this definition in the past is probably correct. But it doesn't help. Scientists can make up new definitions.
Furthermore, while it's also true that planetary scientists call lots of things planets, the report itself admits that they also use the term for moons. Nobody else is going to start calling Pluto a planet under a definition that also includes moons.
A planet has more than just orbit-clearing characteristics.
Additionally, its mass should be enough to form a spheroid. Pluto looks like a goddam potato.
A planet should stay in its own orbit.
Because the orbit is elliptically challenged, Pluto is sometimes the seventh planet and sometimes ninth, making Neptune sometimes eighth and sometimes ninth. Planets gotta make up their minds.
The fucking tater-shaped object travels all the way out to the Kuiper belt.
It's gotta be a publicity stunt. I smell money somewhere in all this.
It little behooves the best of us to comment on the rest of us.
Seriously there was more literature out there, like the one published in 2006.
But in all seriousness what kind of a stupid basis for a new definition is that? "You can't use this new definition because it's different than the old definition". No shit Shirlock.
In the body of the summary, the phrase "according to new research" should be rewritten to say "according to one person's opinion," since there actually is no research involved.
That's why!
I think that's what typos are for. The publisher doesn't really want to have to change the material.... that sounds like a lot of work.
I think few people would call that a "planet". In common usage, moons orbit planets, planets orbit stars.
The only issue is that there are some other things that orbit stars: asteroids, stellar rings, etc. Among those, planets are objects large enough to have been shaped into a spheroid under gravitation.
Oh, a wanderer by any other name....
https://www.youtube.com/c/BrendaEM
If Pluto identifies as a planet then I think we should respect that decision. Maybe Pluto is astronomical body fluid, one day a planet, the next day not.
Right, let's get this straightened out. Just like we did with planet "Urectum".
https://www.youtube.com/watch?...
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The official IAU definition sucks, but it makes more sense to think of Pluto as part of a class of objects of which it is the largest. Eris being the second. These icy objects are very different than the inner planets (celestial objects are really a spectrum and hard definitions can be difficult (see brown dwarf, not a star, not really a planet). But what matters is what astronomers and planetary scientists think is conceptually useful. Even when Pluto was discovered it wasn't clear it should be called a planet. Ceres was considered to be a planet for a lot longer than Pluto was. Though I was excited when one of the proposed IAU definitions alongside what became the official definition would have classified it as a planet.
Blut Pluto is a world in it's own right now that we've visited it. It's a place. So is Ceres, Vesta, even P/67 Churyumov–Gerasimenko is a world now that we've been there. They are no longer points of light or blurry objects in our telescopes. I use world as a poetic term not a scientific one. I know this comment is short on details arguing against considering Pluto a planet but considering it a world.
The other reason I don't want Pluto to be re-classified as a planet is because people would lose interest in astronomy and forget about. It keeps people engaged in the debate. However, if you want to call it a planet, fine. I'll call it a world.
"You'll get nothing, and you'll like it!"
So you mean to tell me Carl Sagan 2.0 Neil SmokesGrass Tyson aka Sinbad from the 1980's was wrong?
Why is that a problem? There are dozens of moons just orbiting Jupiter. The point of a definition is to group things that are alike, not to maintain an easily memorized list.
It makes a huge difference. Basically, if you can't classify Pluto then there's no point in bothering with astronomy or planetary science since you can't predict or classify. In fact, you might as well jump off a building since it renders science and modern life futile if you cannot predict or classify. You're left only with religion.
One, and only one, designation will be useful in any predictive or functional sense. To use any other designation is the work of mystics, not planetary scientists.
What that designation is can be determined only by looking at what has actual scientific value, not what has votes in a conference.
Understood? Good.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
No. The eggheads didn't attend the IAU conference. Most aren't even astronomers.
This hasn't been settled because nobody agrees on the basis. The IAU doesn't want school textbooks with 22 planets in the solar system, the some reason for reclassifying. Planetary scientists don't give a crap about the books and want a definition with actual meaning.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Pluto isn't on the same axis as the other planets and it gets inside the orbit of another planet. If it never was classified as a planet there's no argument for making it one now.
Of some certain density, or at least have sufficient gravity to do so. If that means kicking Mercury out of the club along with Pluto, so be it!
(T>t && O(n)--) == sqrt(666)
Any definition of planet has to be true for:
All objects universally agreed on in our solar system to be planets
All exoplanets of Earth size or larger
All rogue planets that are not brown dwarfs
All planets within accretion disks
This basically means you can't use shape, orbit or objects in proximity in your definition.
Your definition must exclude all:
Rocky asteroids
Rubble pile asteroids
Comets
Brown dwarves
Stars
Dead stars in orbit around other stars
That's not going to be easy, since a lot of characteristics are shared.
Finally, any definition must be as simple as possible and predictive. On seeing a new planetary object, given a certain perfect subset of characteristics plus the definition, we must be able to infer at least one other thing about the object. Otherwise, it's not a useful definition.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It's what I learned in school back in the 1980's and it is still true now.
Corporatism != Free Market
The classification of "planet" is mainly for the benefit of the general public. This is a pragmatic decision that helps keep knowledge of the Universe accessible and manageable for the masses. Sorry planetary scientists but your needs are secondary. Relax, you'll survive this.
Proposal: the next planet we discover should be named Snoopy.
You are incorrectly assuming that 'clearing it's orbit' is to be interpreted literally. It's not!
'Clearing its orbit ' doesn't mean an planet's orbit is completely devoid of any object, whether it's an asteroid hundreds of miles across. or a grain of sand. An object that is gravitational dominant in its orbit, has no other objects of comparable size in it's orbit and is not under the gravitational influence of any other objects with the exception of it's satellites has 'cleared it's orbit' and along with other criteria is classified as a planet.
Every day Earth, and every other large object in our solar system, is bombarded with thousands of meteors, most smaller than the grain of sand. Applying a literal definition of 'clearing it's orbit' would mean Earth is not a planet since these micro-meteors remain in its' orbit.
Pluto was mistakenly classified as a planet in the first place as I believe, and this comes from not always perfect memory, astronomers were looking for Planet X and Pluto just happened to be where PX was predicted, and they originally thought Pluto was much more massive than what it turned out to be.
Right, let's get this straightened out. Just like we did with planet "Urectum".
https://www.youtube.com/watch?...
Urectum hell - damn near killed him.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
Basically, if you can't classify Pluto then there's no point in bothering with astronomy or planetary science since you can't predict or classify
...? You trailed off there. If you can't classify Pluto as a planet or a non-planet, you can't predict what about it? Seems like knowing its size, chemical makeup, etc. would be way more useful than knowing its IAU classification.
The opinions stated herein do not necessarily represent those of anybody at all. Deal with it.
If those follow a pattern for a certain class of objects, you can give the class a name.
If there is no class, you can't predict. Every observation is unique and devoid of meaning.
Those are your choices. Order or randomness.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Basically, if you can't classify Pluto then there's no point in bothering with astronomy or planetary science since you can't predict or classify.
This is beyond retarded. Pluto has been classified in different ways over the last decades. Did people stop doing astronomy or planetary science in any of those periods ?
...Pluto wasn't the only "planet" discovered by a US american. This discussion is not about science, it is about the bloated ego of a nation where pressure is measured in pounds per square foot....
The original word planet means a wandering start, a distant light in the sky. Now that we know more about those distant lights, we could have better words to describe them, based on mass instead.
For example, "Piccolo" for meteors, "Magnum" for rocky planets, "Jeroboam" for giant planets, "Rehoboam" for small stars etc.
You trailed off again there. "If there is no class, you can't predict..." ...what? Throwing around hilarious hyperboles like "devoid of meaning" and "those are your choices, order or randomness" and "you might as well jump off a building" takes the spotlight off the fact that nobody's really using the "planet" classification to predict anything specific, simply because the definition is so ad-hoc, and there's no real tweak to it that makes it significantly more useful than it is now.
The opinions stated herein do not necessarily represent those of anybody at all. Deal with it.
Wrong split. And that is why that particular split is useless.
Rather than split between two magnitudes (which is rarely helpful), you split between two categories (which is).
You can categorise between reflection, refraction and diffraction. THAT is the correct division.
You have demonstrated precisely why arbitrary classes are useless, why you must use classes that have distinct, predictive, meaning. You have shown why value-based definitions are abhorrent, why classifications should have intrinsic rather than extrinsic meaning.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Look, it's very simple.
A definition should have certain properties.
First, any classification is itself a hypothesis and must therefore follow all the rules governing a hypothesis. This includes the ability to predict, since a hypothesis must be falsifiable.
Second, if you contend that nothing in the observable universe can be categorized or understood by science, what else could you call it but random? Even most religions have structure and rules that science could infer. If you have no such structure, if science is useless for prediction, you have nothing. That's hardly hyperbole, science is the study of relationships and systems. You seem to be arguing neither exist. I suggest that's not what you intend to be arguing, but it's hardly my fault if zero correlation between all parameters is indistinguishable from a random oracle.
Second, there are plenty of definitions far more useful than the IAU one.
Here's one. A planet is a gravitationally-rounded object with a single core and stratification that formed in part or whole in a planetary accretion disk.
There's not a single asteroid or comet that meets that definition. It makes no reference to stars, it's invariant and wholly intrinsic. It allows for sub-classes, rather than wholly independent planetary-like objects. It applies to all known exoplanets and rogue planets. It does not apply to solid bodies formed from dead white dwarfs.
What's more, it's predictive. It is stating that masses of similar size formed in accretion disks are going to behave differently to those formed in stellar nurseries, since it is saying there is linear separation between those two types of mass.
It is stating that there is a fundamental difference between comets (multi-core), asteroids (no core) and planets, that these can be linearly separated and that fundamental properties present in one group will not appear in another.
These predictions are falsifiable, therefore this is a valid hypothesis, It is predictive, therefore it is superior to the IAU one which is not. It is also far, far better science.
As geeks, we should appreciate science above and beyond personalities.
From this definition, I can create an ontology, a PROPER ontology.
I can separate out planets with solid, liquid and gaseous cores, and likewise for the mantle. Solids in a liquid are still in a liquid, even if the solids are the bulk of what is there. In terms of predicting what will happen, the liquid would be what mattered. I'm only concerned with intrinsics and invariants, so the ability to behave as a liquid is important for some solids and would be an important subclass but they're still solids.
Some gas giants will have super Earths inside, these will obviously behave differently from gas giants that don't. Proxima b may have started as a gas giant and had the atmosphere removed, but that won't affect the rocky interior. And how thick does the atmosphere have to be? Clearly, this is not a linearly separable parameter and as I've explained elsewhere those simply aren't valid criteria. You can distinguish spectrums, but you cannot distinguish points on a spectrum.
Therefore I cannot usefully define a rocky planet or a gas giant, but I can define the composition of a given layer and I can make predictions based on that.
So I now have planets, planets with a specific core type, planets with a specific core and mantle type.
We can categorise composition by specifying the generation of star. So a G3 planet formed around a third generation star, somewhere, and the ratio of elements reflects that.
If I can do that, a planetary scientist with decades more experience and understanding can do a thousand times more.
I'm not calling this ideal, I'm calling this valid, good science and predictive. There will be far better ontologies, that's irrelevant. This is an ontology that guarantees linear separation and prediction, keeps things simple and doesn't have any weirdness or freaky arbitrary values.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
No more voting when just about everyone has already left the conference. If the full membership were there Pluto would still be a planet. It was stupid to do what they did.
Homer called. He needs a seeing-eye to help him do the paperwork for his copyright suit,
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
I suspect "Snoopy" would fail on copyright grounds.
Enjoy building your telescope and doing your searches. Odds-on, it'll take a fraction of the rest of your career.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
...Patrick Moore playing the xylophone.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Absolutely. It's probably one of the stupider reasons the IAU put out.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
I love the T-shirt going around:
PLUTO
Never Forget
1930-2006
Apparently some people are taking this as more than a joke!
Just think, to avoid the controversy, the IAU should have just made two proposals.
The "traditional solar system". With the nine planets.
The the "modern definition" and the 8 major planets and the ever increasing number of minor planets, and planet X, and probably eventually the remains of Krypton.
Little need to re-write the books, just note that you are using a traditional definition, or a modern definition.
Q:I was listening to a CD in Grip and it sounded horrible! What's up? A:Perhaps you are listening to country music