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Is Pluto a Binary Planet?

samzenpus posted about 2 years ago | from the twice-as-fun dept.

Space 275

astroengine writes "If the Pluto-Charon system were viewed in a similar way to binary stars and binary asteroids, Pluto would become a Pluto-Charon binary planet. After all, Charon is 12% the mass of Pluto, causing the duo to orbit a barycenter that is located above Pluto's surface. Sadly, in the IAU's haste to define what a planet is in 2006, they missed a golden opportunity to define the planetary binary. Interestingly, if Pluto was a binary planet, last week's discovery of a fifth Plutonian moon would have in fact been the binary's fourth moon to be discovered by Hubble — under the binary definition, Charon wouldn't be classified as a moon at all."

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275 comments

IAU? Haste? No way. (5, Interesting)

girlintraining (1395911) | about 2 years ago | (#40658519)

The IAU has been trying to redefine things in bulk, and then growing discontent with those definitions and changing them yet again. It's a far cry from the organization's original role: Cataloging astronomical objects. To put it in perspective, they're like a librarian that changes the layout of the indexing system weekly. They don't actually move the books around, but they rename the aisles, recategorize things, and generally make a massive mess of it all.

But then, I'd expect nothing less from a committee of pseudo-scientists; They're so engrossed with their own administrations they've become cut off from the people they're supposed to be helping.

Re:IAU? Haste? No way. (-1, Troll)

Anonymous Coward | about 2 years ago | (#40658545)

Who cares about a fucking Binary Planet. Children are starving in Africa and you give a shit about a fucking Binary Planet? Fuck you. Instead of shooting electron beams at a Binary Planet to see what happens these scientists should be in the wheat fields growing food for starving children in 3rd world countries. First world fuckers like yourself are decadent faggots who care more about a Binary Planet than humans. Those same starving children probably mined the Binary Planet for you so you could play with it in your lab. Fuckers.

Re:IAU? Haste? No way. (-1)

Anonymous Coward | about 2 years ago | (#40658601)

This always makes my day.

Re:IAU? Haste? No way. (-1)

Anonymous Coward | about 2 years ago | (#40658621)

Who cares about a fucking Binary Planet. Children are starving in Africa and you give a shit about a fucking Binary Planet? Fuck you. Instead of shooting electron beams at a Binary Planet to see what happens these scientists should be in the wheat fields growing food for starving children in 3rd world countries. First world fuckers like yourself are decadent faggots who care more about a Binary Planet than humans. Those same starving children probably mined the Binary Planet for you so you could play with it in your lab. Fuckers.

How many have you adopted personally? If less than ten, then you are a hippocrite.

Also what happens when an extinction event happens on earth and we don't have any humans in space yet because of the starving children? There are no children left to be hungry.

Re:IAU? Haste? No way. (-1)

Anonymous Coward | about 2 years ago | (#40658807)

There are no children left to be hungry.

Mission accomplished.

Re:IAU? Haste? No way. (-1)

Anonymous Coward | about 2 years ago | (#40659323)

Your momma's a binary planet!

Re:IAU? Haste? No way. (0)

Anonymous Coward | about 2 years ago | (#40658747)

Right, I totally forgot about my responsibility to feed ALL HUMANS for a minute there.

Re:IAU? Haste? No way. (-1)

Anonymous Coward | about 2 years ago | (#40658995)

Kill yourself and be protein for the kiddies

Re:IAU? Haste? No way. (-1, Flamebait)

Anonymous Coward | about 2 years ago | (#40659155)

Fuck Africa and all the niggers on the continent. Shittiest motherfucking continent on the planet. Why don't you do us all a favor by going to Africa yourself, and starve with them and share diseases as you kiss their ass.

Re:IAU? Haste? No way. (0)

Anonymous Coward | about 2 years ago | (#40658599)

Just a question. Are you a "real" scientist?

Re:IAU? Haste? No way. (5, Funny)

Doubting Sapien (2448658) | about 2 years ago | (#40658983)

I'm a Christian Scientist, you insensitive clod!

Re:IAU? Haste? No way. (4, Insightful)

starless (60879) | about 2 years ago | (#40658745)

Why do you call the committee members pseudo-scientists? I'm rather sure everyone has a PhD in astronomy/astrophysics. (I'm technically an IAU member, although I've had little involvement with it.)

Re:IAU? Haste? No way. (-1)

girlintraining (1395911) | about 2 years ago | (#40659029)

Why do you call the committee members pseudo-scientists? I'm rather sure everyone has a PhD in astronomy/astrophysics. (I'm technically an IAU member, although I've had little involvement with it.)

They don't experiment. They don't work in a lab. They may be involved in the scientific community, but they're not doing any scientific work per-se. They're bureaucrats with training in science.

Re:IAU? Haste? No way. (4, Informative)

starless (60879) | about 2 years ago | (#40659099)

Why do you call the committee members pseudo-scientists? I'm rather sure everyone has a PhD in astronomy/astrophysics. (I'm technically an IAU member, although I've had little involvement with it.)

They don't experiment. They don't work in a lab. They may be involved in the scientific community, but they're not doing any scientific work per-se. They're bureaucrats with training in science.

Can you specify some names so I can check this is really true?
(Not many of us astronomers work in labs or experiment anyway. We mainly obtain and analyze data, construct theoretical models. A smaller number of us work on instrumentation which might involve working in an actual lab.)

Re:IAU? Haste? No way. (4, Informative)

GrumpySteen (1250194) | about 2 years ago | (#40659217)

It would be virtually impossible to name names. The reclassification of Pluto (among other things) was the result of a vote held at the end an IAU General Assembly where only 424 out of roughly 9000 members actually voted [wikipedia.org] .

Re:IAU? Haste? No way. (1)

FunkDup (995643) | about 2 years ago | (#40658795)

They don't actually move the books around, but they rename the aisles, recategorize things, and generally make a massive mess of it all.

Astronomical knowledge is evolving quite a bit faster than the rest of the library. I'm not necessarily saying that any IAU decisions are correct but I don't see anything fundamentally wrong with recategorizing. Isn't it that a hallmark of the intelligent?

Re:IAU? Haste? No way. (0)

SJHillman (1966756) | about 2 years ago | (#40658999)

No, it's a hallmark of the bored with too much free time. If you had an employee who spent most of their time recategorizing rather than coming up with something new, would you consider them intelligent? You'd probably think they were lazy or incompetent.

Re:IAU? Haste? No way. (5, Insightful)

girlintraining (1395911) | about 2 years ago | (#40659111)

Astronomical knowledge is evolving quite a bit faster than the rest of the library. I'm not necessarily saying that any IAU decisions are correct but I don't see anything fundamentally wrong with recategorizing. Isn't it that a hallmark of the intelligent?

No. I can write a computer algorithm to sort something; that doesn't make it intelligent. Anyone can make something more complicated -- true genius is making things simpler.

Re:IAU? Haste? No way. (4, Funny)

lennier (44736) | about 2 years ago | (#40659097)

But then, I'd expect nothing less from a committee of pseudo-scientists

You, sir, have very low expectations for the noble profession of pseudo-science. I both demand and expect a whole lot more from my committees of space pseudo-scientists:

1. At least three separate and conflicting theories about the catastrophic formation of the solar system as a result of an interplanetary war between four and eight thousand years ago.
2. A dozen formulations of the Lorentz Contraction as a result of the pre-Einsteinian ether
3. A gigantic laser mounted on Mimas [wikipedia.org]
4. A baroque dying Martian civilisation clustered in glorious decadent splendour among the Red Weed entwined canals and pentagonal pyramids of Cydonia.
5. Ancient space Egyptians and Mayans with lasercats.
6. Space Mormons versus robots.
7. A literary analysis of Shakespeare's Hamlet as really being about the precession of the equinoxes.
8. An apocalyptic prediction involving Halley's Comet.
9. An Electric Universe theory, preferably one that makes Saturn a former star.
10. A homebuilt antigravity demonstration device harnessing the awesome power of magnets.

Yes? (2)

n5vb (587569) | about 2 years ago | (#40658523)

As closely as they orbit each other, I'd say Pluto-Charon would be almost the example of such a system. Heck, it's almost a Rocheworld. :p

Sun is the same way (4, Informative)

mister_playboy (1474163) | about 2 years ago | (#40658533)

The barycenter of the Sun/Jupiter system lies at 1.07 solar radii from the Sun's core (i.e. outside the Sun). Is the Sun a binary star?

For those curious, the barycenter of the Earth/Moon system is well inside the Earth, despite the Moon relatively energetic orbit.

Re:Sun is the same way (2, Insightful)

Anonymous Coward | about 2 years ago | (#40658607)

Wouldn't Jupiter need to be a star? Short of us igniting it, I think that is going to be a problem.

Re:Sun is the same way (2)

Samantha Wright (1324923) | about 2 years ago | (#40658619)

Damn! You're right! Where's Arthur C. Clarke when you need him...

Re:Sun is the same way (3, Informative)

Kickasso (210195) | about 2 years ago | (#40658639)

Well, it does radiate more energy than it gets from the Sun...

Re:Sun is the same way (1)

siddesu (698447) | about 2 years ago | (#40658687)

But that is not due to nuclear reactions in the core, as would be the case with a star. And it is too small to even be a brown dwarf.

Re:Sun is the same way (5, Informative)

mooingyak (720677) | about 2 years ago | (#40658697)

If the mass part counts at all (Charon being 12% of Pluto's mass), Jupiter is a far smaller fraction of the Sun's mass (something like 0.1% if I did the math right).

Re:Sun is the same way (1)

arisvega (1414195) | about 2 years ago | (#40658721)

After all, Charon is 12% the mass of Pluto

The barycenter of the Sun/Jupiter system [..] Is the Sun a binary star?

Jupiter is less than 0.1% the mass of the Sun

Re:Sun is the same way (2)

Hentes (2461350) | about 2 years ago | (#40658729)

Depends on how do you define the radius of the Sun.

Re:Sun is the same way (2)

realityimpaired (1668397) | about 2 years ago | (#40658977)

Most people would consider the radius of the Sun to end where the mass of burning fusion ends, which is fairly constant except for solar flares... though I do get your point. If we include the atmosphere in our calculation of the solar radius, then Jupiter is actually within the heliosphere.

Re:Sun is the same way (-1)

Anonymous Coward | about 2 years ago | (#40658985)

Ah, in that case, Jupiter isn't a planet.

"a planet is a celestial body which: is in orbit around the Sun,"

Teeeeeeeeeeeeeeeechnically, jupiter is orbiting a barycenter outside the Sun.

Now it makes sense (1, Offtopic)

Megahard (1053072) | about 2 years ago | (#40658565)

The Death Star was so massive that when it orbited a planet it became a binary system.

Re:Now it makes sense (5, Funny)

spire3661 (1038968) | about 2 years ago | (#40658645)

Ugh. The entire idea of the 'death star' shows how little imagination Lucas has. Even moving the death star into a system would effect the planetary orbits. Why would you need a big laser gun when you can simply wobble a planet out of its habitable orbit using the gravity of your space station.

Re:Now it makes sense (0)

Anonymous Coward | about 2 years ago | (#40658655)

Speed?

Re:Now it makes sense (1)

siddesu (698447) | about 2 years ago | (#40658715)

True of all doom weaponry in most sci-fi movies. It has to look good on screen, not to be scientifically plausible. The audience of the star wars movies are the 7-14 y.o. children, after all.

Re:Now it makes sense (4, Funny)

idji (984038) | about 2 years ago | (#40658781)

because you want results in seconds, not aeons.

Re:Now it makes sense (1)

n5vb (587569) | about 2 years ago | (#40658883)

Ugh. The entire idea of the 'death star' shows how little imagination Lucas has. Even moving the death star into a system would effect the planetary orbits. Why would you need a big laser gun when you can simply wobble a planet out of its habitable orbit using the gravity of your space station.

Wouldn't take much, if you pick the right resonant orbit and aren't in a hurry .. ;)

Re:Now it makes sense (5, Informative)

canajin56 (660655) | about 2 years ago | (#40658889)

The first death star was 160 KM in diameter, so a radius of 80 KM. If you assume the same mass density as, say, an aircraft carrier or other military vessel (about 0.15 kg/m^3), you end up with a Death Star that masses about 3e14 KG. That's absurdly heavy to realistically have engines zipping it about, but it's not going to result in major and instantaneous disruptions of orbits. Even Mars' tiny moon Phobos has 100 times the mass. Although the Death Star II from RotJ was supposed to be 900KM across, so that would put it about even with the mass of Phobos. Put another way, the Earth masses 10,000,000,000 times as much (or only 100,000,000 for the Death Star II), so I don't see how the Death Star is going to be winning that gravitational tug-of-war. If you want to argue "Well maybe they have super cool tractor beams so they can amplify their gravitational pull and their massive engines can keep them stationary while they're doing it!" the obvious counter is "They don't, that's why they went with the laser, since they thought about it. Also big laser is more menacing in a platform which has the primary purpose of intimidation. Additionally the big laser doubles as a way to destroy enemy capital ships from well outside their own engagement radius".

Re:Now it makes sense (1)

Anonymous Coward | about 2 years ago | (#40659251)

This post was better in the original Klingon.

Re:Now it makes sense (0)

Anonymous Coward | about 2 years ago | (#40659349)

The first death star was 160 KM in diameter, so a radius of 80 KM. If you assume the same mass density as, say, an aircraft carrier or other military vessel (about 0.15 kg/m^3), you end up with a Death Star that masses about 3e14 KG. That's absurdly heavy to realistically have engines zipping it about, but it's not going to result in major and instantaneous disruptions of orbits. Even Mars' tiny moon Phobos has 100 times the mass. Although the Death Star II from RotJ was supposed to be 900KM across, so that would put it about even with the mass of Phobos. Put another way, the Earth masses 10,000,000,000 times as much (or only 100,000,000 for the Death Star II), so I don't see how the Death Star is going to be winning that gravitational tug-of-war. If you want to argue "Well maybe they have super cool tractor beams so they can amplify their gravitational pull and their massive engines can keep them stationary while they're doing it!" the obvious counter is "They don't, that's why they went with the laser, since they thought about it. Also big laser is more menacing in a platform which has the primary purpose of intimidation. Additionally the big laser doubles as a way to destroy enemy capital ships from well outside their own engagement radius".

Yeah, sure. In an imaginary universe full of unrealism, "The Death Star is too heavy to move!" is at the top of your list?

Re:Now it makes sense (1)

Anonymous Coward | about 2 years ago | (#40658923)

If I remember correctly, in one of the star wars books Han and Chewbakka discover an ancient system of giant repulsors embedded in a planet to change its orbit. It was also said, while everyone in the universe uses them and knows how to make them, nobody actually knows how or why they work as they do.

Re:Now it makes sense (0)

Anonymous Coward | about 2 years ago | (#40659221)

Was that in regard to repulsors or hypderdrives? I thought it was the latter....

Re:Now it makes sense (0)

Anonymous Coward | about 2 years ago | (#40659159)

Ugh. The entire idea of the 'death star' shows how little imagination Lucas has. Even moving the death star into a system would effect the planetary orbits. Why would you need a big laser gun when you can simply wobble a planet out of its habitable orbit using the gravity of your space station.

Won't work.

Why?

Because it's not a moon, damnit!

Re:Now it makes sense (1)

Cold hard reality (1536175) | about 2 years ago | (#40658669)

Which then became a unary system again.

Re:Now it makes sense (0)

Anonymous Coward | about 2 years ago | (#40658887)

The Death Star probably isn't that massive. The one from RotJ, especially, was mostly hollow.

Re:Now it makes sense (2)

turbidostato (878842) | about 2 years ago | (#40659203)

"The Death Star was so massive that when it orbited a planet it became a binary system."

But of course it's a binary system: that's no moon.

It's not a planet at all. (0)

Anonymous Coward | about 2 years ago | (#40658587)

Haven't you heard? Pluto isn't a planet at all anymore.

Barycenter based definition has issues (5, Informative)

Anonymous Coward | about 2 years ago | (#40658603)

The issue with using the barycentre, is by moving two objects further apart without changing the mass, eventually the barycentre will be above their surfaces. The Jupiter-Sun barycentre is above the surface of the sun, but wouldn't be if Jupiter were closer. The Earth-Moon barycentre is about 75% of the radius of the Earth, but if the distance between them increased by about 25%, then the Earth-Moon barycentre would be above Earth's surface. So it is quite possible to have two bodies that are very influential on each other, but with the barycentre below the surface due to being too close. And the status could change simply by having one body move further away, like Earth's moon is currently doing.

So now the count becomes (1)

Anonymous Coward | about 2 years ago | (#40658609)

8 regular planets, plus the Pluto-Charon binary which adds 10 more.

Too small (-1, Troll)

cpu6502 (1960974) | about 2 years ago | (#40658625)

Pluto is too small to be considered a planet, binary or otherwise.

Re:Too small (0)

Anonymous Coward | about 2 years ago | (#40658779)

only for the small minded.

Re:Too small (-1, Troll)

Anonymous Coward | about 2 years ago | (#40658785)

Pluto is too small to be considered a planet, binary or otherwise.

Too small,
Highly excentric orbit, goes way above and below the ecliptic plane
It intersects the orbit of inner planets

and the kuiper belt objetcs are just like Pluto.

So unless you have an arbitrary (and non scientific) definition of what a planet is, you're going to find that our solar system has tens of thousands of planets. And this is simply ridiculous from a scientific classification viewpoint.
Scientific classifications can't be too broad that just about anything can fall in, and they can't be too narrow that you can't get any "sensible data" out of it.

So sorry for the american kids that "love" pluto, but science progresses. And one side of that progress is that we come up with new classification schemes justified by new data we gather.

Re:Too small (1)

bunratty (545641) | about 2 years ago | (#40658817)

The problem is not that it's too small. It's large enough to be a spheroid, so it's large enough to be a planet. If it existed in an orbit that was free of other large objects (e.g. Neptune and Kuiper belt objects), it would be a planet.

Re:Too small (1)

gman003 (1693318) | about 2 years ago | (#40658833)

Except that, as of now, the *definition* of a planet involves "an orbit [...] free of other large objects". So that's like saying "the Moon would qualify as a planet if it orbited the Sun instead of the Earth", or more succinctly, "Pluto would be a planet if it weren't for the things that make it not a planet".

Re:Too small (0)

Anonymous Coward | about 2 years ago | (#40658955)

The (IAU) definition also includes "is in orbit around the Sun,"

That means that there is no such thing as a planet outside the solar system.

Re:Too small (0)

Anonymous Coward | about 2 years ago | (#40659149)

The (IAU) definition also includes "is in orbit around the Sun,"

That means that there is no such thing as a planet outside the solar system.

Hey thats why the term exo-planet was invented.

Re:Too small (1)

bunratty (545641) | about 2 years ago | (#40659001)

My point is that one of those things is *not* its size.

Re:Too small (0)

Anonymous Coward | about 2 years ago | (#40658861)

The problem is not that it's too small. It's large enough to be a spheroid, so it's large enough to be a planet. If it existed in an orbit that was free of other large objects (e.g. Neptune and Kuiper belt objects), it would be a planet.

So according to your definition Titan would be a planet, were it not for that pesky Saturn just over Titan's horizon.

Re:Too small (1)

bunratty (545641) | about 2 years ago | (#40658979)

It's not *my* definition. It's *the* definition. Yes, Titan would be a planet if it were in its own orbit, as would most of the solar system's largest moons.

Pluto never was a planet (4, Interesting)

TheGoodNamesWereGone (1844118) | about 2 years ago | (#40658653)

I do not understand at all the rage over Pluto's demotion from planetary status. Is it tradition? 'Traditionally' the Sun was thought to revolve around the Earth. Is it because children have to be sat down and gently told the truth, like about Santa Claus? Is it something more personal between individuals in astronomy? It's called *science* folks, and it's self-correcting. I just don't get why people are so upset.

Re:Pluto never was a planet (3, Insightful)

spire3661 (1038968) | about 2 years ago | (#40658777)

Humans fear all change.

Re:Pluto never was a planet (-1)

Anonymous Coward | about 2 years ago | (#40658965)

Humans fear all change.

No, just american kids.

Re:Pluto never was a planet (1)

Fujisawa Sensei (207127) | about 2 years ago | (#40659049)

The kids aren't as bad as their parents are.

Re:Pluto never was a planet (5, Informative)

Anonymous Coward | about 2 years ago | (#40658847)

"Is it something more personal between individuals in astronomy?"

This, actually. Long story short, there are two camps of astronomers. One of them characterizes bodies based on where they're orbiting, the other characterizes bodies based off what they're made of.

The former pushed this through as an act of political dickmanship on the last day of a conference (after most participants had gone home), in a only tangentially related addition to a talk scheduled for a different topic, breaking IAU rules to do so. It's not a 'scientific' decision, it's a purely political one.

And any definition that has a category 'dwarf planet' that isn't a subset of 'planet' is about as stupid as redefining 'car' so that 'electric cars' are no longer a subset of 'cars'.

Re:Pluto never was a planet (5, Insightful)

TheGoodNamesWereGone (1844118) | about 2 years ago | (#40659051)

I figured it had something to do with dick-waving. I'm not a professional astronomer, don't play one on TV, but I've had an abiding love for the subject since I was growing up in the 60s. If you use the orbital argument then it makes sense, because Ceres, too was thought to be a planet in 1801 (It accorded nicely with the 'traditional' Bode's Law). It didn't take long for the scientific community to figure out thought, after Vesta, Juno, and other asteroids were found that these were just the largest members of a population of many; we now estimate hundreds of thousands. Likewise the compostional argument works in favor of demotion as well. Working outward we have rocky inner planets, two gas giants, two ice giants, and then a buttload of comparitively very tiny solid icy bodies, that when they get perturbed and wander closer, get called comets. I don't understand the emotion behind the debate. in 1801 the asteroid belt wasn't known, so they called Ceres a planet. In 1930 the Kuiper belt wasn't known, so they called Pluto one. We've learned differently. What's all the fuss?

Re:Pluto never was a planet (0)

Crypto Gnome (651401) | about 2 years ago | (#40659229)

I figured it had something to do with dick-waving.

I am not entirely what This Guy [facebook.com] has to do with the issue, please clarify.

Re:Pluto never was a planet (1)

Anonymous Coward | about 2 years ago | (#40658857)

Re-defining pluto as a non-planet wasn't really scientific progress at all. It was primarily to save us from having to claim *lots* of other things as planets and moving from 9 planets to hundreds or perhaps thousands of them. It wasn't as if some amazing new discovery that progressed our understanding of the universe occurred. It was basically some people being uppity about semantics.

Re:Pluto never was a planet (0)

Anonymous Coward | about 2 years ago | (#40658905)

Re-defining pluto as a non-planet wasn't really scientific progress at all. It was primarily to save us from having to claim *lots* of other things as planets and moving from 9 planets to hundreds or perhaps thousands of them. It wasn't as if some amazing new discovery that progressed our understanding of the universe occurred. It was basically some people being uppity about semantics.

Yes it was scientific progress. In 1930 when Pluto was discovered no one knew about the Kuiper belt objects.
Hell until recently the term planet wasn't even defined scientifically. The greek term planet means "a star that wanders across the sky". A useful definition 2000 years ago when the only objects in the sky were stars (and new stars) and comets. But with the discovery of hundreds, thousands of exoplanets and the discovery of objects that have the same "properties" as that of Pluto in the Kuiper belt; a scientific definition was in order. It was needed to make a classification scheme that is rational and devoid of "I'll know a planet when I see one" type of reasoning.

Re:Pluto never was a planet (1)

Sperbels (1008585) | about 2 years ago | (#40659297)

It's not scientific progress to discover that our solar system is littered full of Pluto like objects? Frankly, I never understood this whole periodic table nonsense. You've got your earth, your water, your air, and your fire. Why make it complicated and stuff? And why demote Fire? The kids liked Fire. Now we have to change all the text books.

Re:Pluto never was a planet (1)

lorinc (2470890) | about 2 years ago | (#40658859)

Haven't you recognized her cries when she heard the news of her destitution? You insensitive clod!

Re:Pluto never was a planet (4, Insightful)

Baloroth (2370816) | about 2 years ago | (#40658929)

To say it "never was a planet" is not quite true. It never was a planet according to the definition of planet that we use now, but it was a planet according to the definition we used to use. If you change the definition, people are going to be confused. It has nothing to do with tradition (except insofar as language is a "tradition"), and everything to do with the alteration of the language. Now, that alteration may be fully scientifically justified and acceptable... but it's still going to annoy people.

The comparison with the geocentrism is a little faulty. The issue here has very little to do with our knowledge of reality changing (it didn't really), but with the way we look at that reality changing (i.e. the words used for a thing).

It's not science, it's linguistics. The result is even now what category Pluto falls into can be debated: we could quite easily call it a planet even now, the problem is the definition would be too wide and force us to call things planets not traditionally called planets. So somewhat contrary to your point, a large part of the reason Pluto isn't called a planet anymore is actually tradition: because we don't want to call all the Kuiper belt objects planets also.

Re:Pluto never was a planet (1)

Sarten-X (1102295) | about 2 years ago | (#40658947)

A lot of money was wasted making those silly 9-letter acronyms to be printed in hundreds of thousands of textbooks, and now they all have to be redone! The economic burden is astronomical.

Re:Pluto never was a planet (0)

Anonymous Coward | about 2 years ago | (#40658971)

No it's because there were "scientists" around the world that needed to write a new paper to proclaim their relevancy that caused people to distrust them. People saw they had a poor hypothesis, distrusted it because of lack of evidence and the fact that they proclaimed everyone in the past was wrong, and that they were soooo much smarter then anyone else, that caused people to say "pffffff". Guess what, they were wrong. So much for their credibility.

Re:Pluto never was a planet (1)

styrotech (136124) | about 2 years ago | (#40658989)

Is it because children have to be sat down and gently told the truth, like about Santa Claus?

Now that you mention children - my five year old is in denial. He still insists that Pluto is a planet. Even if the reclassification was just before he was born. The set of plastic planets hanging from his ceiling (his first ever Solar System experience) included Pluto, and no new library book or educational dinner table placemat since has managed to convince him otherwise.

I'm sure he would be far less upset after learning the truth about Santa (I think he was always a bit sceptical about that as a concept).

If only I had accidentally 'lost' Pluto when hanging up his planets all those years ago...

Re:Pluto never was a planet (1)

dotgain (630123) | about 2 years ago | (#40659181)

I think what's probably more important to your son is not the semantics of what we do and do not classify as a planet, but what is actually out there.

And apparently nor is Neptune (1)

Anonymous Coward | about 2 years ago | (#40659003)

... since the orbit of Pluto crosses that of Neptune and therefore Neptune has not cleared out its region of space yet, and probably never will.

Seriously, these IAU definitions are just plain silly and have no hard scientific basis.

The astronomers really ought to create themselves a technical system of classification for scientific use which allows a body to be several things at once, and leave the lay public to their sloppy (but not unreasonable) traditional names for things.

Re:Pluto never was a planet (0)

Anonymous Coward | about 2 years ago | (#40659193)

You asked...

To be honest, *I* don't understand all the rage that people had over the idea of *keeping* Pluto a planet. The vote was taken, and it won--is that science though?

Here's the problem to me: people arrogantly frame this debate as "if you think Pluto is a planet, you're being emotional and unscientific." However, there's nothing more emotional about the idea that "Pluto is a planet" than the idea that "there can't be lots of planets." To *me*, the whole sense of urgency about changing Pluto's status had to do with some emotional crisis stemming from the irrational idea that "we can't have lots of planets."

The most reasonable definition is the one that goes something like "a body is a planet if its mass/gravity/whatever is sufficient to form a sphere." How is it reasonable to start introducing nonsense things about "clearing its orbit"? It's totally unreasonable and complex, and depends on all sorts of assumptions about the star system the body is in, etc.

Who cares if Vesta and Pluto are both planets? Who cares if there are 100 planets or a 1000 planets? Should we create a contorted definition of a planet to avoid the mental anguish it apparently causes people to think that there are many planets out there? Apparently.

To me the current nonsense definition stems from the same discomfort people felt in learning that the sun doesn't orbit the earth. The current definition was adopted to comfort those who feel threatened that there might be many worlds resembling our own. Don't want to be one of many? Just change the definition to ease your anxiety.

Re:Pluto never was a planet (0)

Anonymous Coward | about 2 years ago | (#40659209)

The Americans were elated when they had found a planet. Now they are upset because their planet was taken away.

Re:Pluto never was a planet (0)

Anonymous Coward | about 2 years ago | (#40659265)

It's not "science", it is semantics. The original definition of planet was "wanderer", meaning a star that wandered the night sky. Scientists still called these objects planets even after they discovered their true nature. There never was a true scientific definition of planet until the scientific community bungled it with their attempt to define planet.

Definition (2)

christurkel (520220) | about 2 years ago | (#40658663)

My proposed definition: A binary system comprises two objects whose common center of gravity is above the surface of either object and the components of the system are similar in size and/or mass. This would Pluto-Charon a binary system and the Sun-Jupiter not a binary system.

Re:Definition (1)

Fred Ferrigno (122319) | about 2 years ago | (#40658801)

and the components of the system are similar in size and/or mass.

How similar is "similar"?

Re:Definition (1)

GodfatherofSoul (174979) | about 2 years ago | (#40659179)

You've now created a new classification by omission. What about formerly binary star systems where one entity far more massive? I like your definition though.

010110010110010101110011 (0)

Lord Lode (1290856) | about 2 years ago | (#40658699)

01010000011011000111010101 11010001101111001 000000110100 1011100110010000 0011000100110100101101110011 000010111001001111 00100101110

Re:010110010110010101110011 (0)

Anonymous Coward | about 2 years ago | (#40658761)

UGx1dG8gaXMgYmluYXJ5Lg==

Re:010110010110010101110011 (1)

cultiv8 (1660093) | about 2 years ago | (#40659141)

50 6c 75 74 6f 20 69 73 20 62 69 6e 61 72 79 2e

Re:010110010110010101110011 (0)

Anonymous Coward | about 2 years ago | (#40659197)

Just incase you're not sure if Pluto is binary or not, here's the checksum:

MD5: 852333694102cdc4c583936b2c7eab78
CRYPT (form: $ MD5? $ SALT $ CRYPT):
$1$ci80qSoG$y88zOhTy7EJbaQCqa9oV8.
(form: SALT[2] CRYPT[11]):
ps1CfOs2dEizY
SHA1: a3821d79a30331372396c60563c2f925f79f0480
RIPEMD-160: cb4f515b98f27062eca9a922f682be10345f8bf4

Article is factually incorrect (1)

Anonymous Coward | about 2 years ago | (#40658709)

It claims the moon has 0.01% of the mass of Earth. In reality, it's closer to 1.2%.

Re:Article is factually incorrect (0)

Baloroth (2370816) | about 2 years ago | (#40658939)

It claims the moon has 0.01% of the mass of Earth. In reality, it's closer to 1.2%.

No, it isn't. It's close to .012%.

Fris7 stop (-1)

Anonymous Coward | about 2 years ago | (#40658755)

sudden =and World will have

Pluto is a binary dwarf planet (0)

Anonymous Coward | about 2 years ago | (#40658757)

There are two independent questions:
1) binary vs non-binary
2) dwarf planet vs planet

No need to bring up (2) in a discussion about (1).

Who cares? (0)

Anonymous Coward | about 2 years ago | (#40658799)

Can I be the first to vote "who cares"? It's just a definition, its not like our understanding of Newtonian gravity rests on correctly assigning things into arbitrary categories. And can we please now get back to important things like arguing about whether C is a low level language?

Re:Who cares? (2)

garyebickford (222422) | about 2 years ago | (#40659263)

And can we please now get back to important things like arguing about whether C is a low level language?

OK, just for you. :D Here goes:

Of course it is a low level language. It was described (by Ritchie, if memory serves - in any case one of the authors/designers) as "a structured PDP-11 macro assembler". I would argue that, by definition, any 'assembler' is a low-level language. I would go farther - any language in which the primary semantics and syntax of the language is closely aligned with the physical movements of data through memory, and operations upon that data, is a low level language - freely admitting that this assertion is a bit of hand-waving, but still has some relevance to the meaning. In other words, if almost everything in the language has to do with loading and, storing single bits or rectangular arrays of data, and arithmetic and logical operations on that data, it's a low level language. (I'm trying - probably badly - to elicit an analogy from the language to the machine operations that are executed as a result.)

By contrast, as one of the early designers of SQL discovered at IBM in the early-mid 1970s noted, "We found that a single sentence of SQL could result in 250,000 machine instructions being executed - that explained why it was so slow." Another primary characteristic of SQL is that one can not easily say by inspecting the code just where in a computer's memory a particular data item is stored. (That particular criterion has been greatly complicated by the rather amazing manipulations of cacheing, threading, multiprocessing and so forth, that used to be part of the operating system (and written in low-level language), and are now in hardware and essentially written in a hardware description language, which is a kind of descendant of C.

So, will that do? I am out of popcorn but I'm on the way to the store. I'll bring some back! :)

No (3, Informative)

gman003 (1693318) | about 2 years ago | (#40658829)

Because Pluto is not a planet.

Binary dwarf planets, sure. That seems a reasonable argument. But even treating Pluto and Charon as a single entity can't upgrade them to planet status.

Pluto is a disney character. (0)

Anonymous Coward | about 2 years ago | (#40658831)

It amazes me how this ~10 year old thread topic won't die even though it is lame as hell.

Less than water? (1)

Anonymous Coward | about 2 years ago | (#40658933)

Charon must have less density than water. How else could it repeatedly sail across the river?

Re:Less than water? (1)

garyebickford (222422) | about 2 years ago | (#40659277)

If it had higher density than water, it would sink, and not sail at all. All boats must have lower density than the medium on which they sail.

That's no moon... (1)

rocketman768 (838734) | about 2 years ago | (#40658963)

...it's half a binary planet.

Re:That's no moon... (0)

Anonymous Coward | about 2 years ago | (#40659253)

How sure are you that it's not a space station?

It s not too big.

Planets, broken concept. (0)

Anonymous Coward | about 2 years ago | (#40659107)

The whole concept of planet is broken, Earth is more like Pluto than Jupiter, it more like many of the moons of Jupiter than the Jupiter and yet the Earth and the Jupiter are classed as the same thing and Pluto and the Earth are not. The answer to how many planets does the solar system have is 4 Gas Giants 4 Rocky bodies that dominate there orbit and hundreds maybe thousands of other objects with enough mass for the gravity to make them round.

A Grand Question (2)

Jetra (2622687) | about 2 years ago | (#40659285)

To all you astrophysicists, astronomers, geeks, nerds, technophiles, astronaughts, cosmonaughts, astrologers, pagans/neo-pagans, and skywatchers all alike:

Does it really, truely matter what Pluto is classified as? Classification is simple once we had time to research it. Seeing as how we still keep stumbling over whether or not it's a planet, dwarf planet , comet, or binary planet, my guess is we need to really re-think the classification of a planet and what forth. With so many objects in the night sky, there is bound to be thin lines between classes. that's where sub-classes come in.

How do you solve that problem? Simple: add one more criteria to classing whether and object is a planet or not - Did it ever, does it, or could it harbor life of any kind? If you believe modern astronomy, the earth is habited and Mars may have been full of life during our solar system's history. There could be life on Titan, so that goes from being a Moon to being a Planet, to me.

While you're bickering over the classification of Pluto, I'm wondering why the hell aren't we figuring out a better way to get to and fro between all of these objects? Somebody, for the love of God, develop a feasible Ion Drive that cuts our travel time by at least a quarter.
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