Pluto is no longer a planet!

[geocajun]

Astronomers Say Pluto Is Not a Planet

PRAGUE, Czech Republic (AP) -- Leading astronomers declared Thursday that Pluto is no longer a planet under historic new guidelines that downsize the solar system from nine planets to eight.
After a tumultuous week of clashing over the essence of the cosmos, the International Astronomical Union stripped Pluto of the planetary status it has held since its discovery in 1930. The new definition of what is - and isn't - a planet fills a centuries-old black hole for scientists who have labored since Copernicus without one.


​

 

[The Theory]

and good riddance.

 

[geocajun]

and good riddance.

I never liked that planet either

 

[mikenet2006]

I never liked that planet either

aww, come on Pluto is the s**t, lol

 

[mikenet2006]

They probably did this because they weren't about to classify possibly hundreds of similar sized objects as planets. It would obscure the more important, and well known planets into a long list of small insignificant rocks.

Newer generations would have had to get up in front of class and name all 200 planets, some grownups believe it or not had a hard enough time remembering all 9 planets. lol

Personally I don't know what to say about this. In a way I still see Pluto as a planet because it is spherical, has a satellite, and is very massive to be a "dwarf Planet" I'll tell you what though, if it is going to be called a dwarf planet, it is without a doubt the largest most complex of them. This decision may be done away with. Astronomers are forming a petition that will try to overturn this new idea.

The scientific reason they demoted Pluto to "dwarf Planet" status, is because it rest in a mass of debre similar to the asteroid belt. I think this decision is a bit Hasty because if Mars were far enough out to be in the asteroid belt would we call it a dwarf planet for this very reason, and cut the number of planets to 7? People are not considering that Pluto is near the size of Mercury, and has its own moon to boot. Obviously it was large enough to be discovered decades ago, unlike other dwarf planets.

It is an interesting concept, I believe its a matter of opinion in the case for Pluto in that it is very small to be a planet, and has a wild orbit that follows a heap of debre. On the other hand it is very complex and over sized to be a Dwarf Planet.

 

[Kripost]

They probably did this because they weren't about to classify possibly hundreds of similar sized objects as planets. It would obscure the more important, and well known planets into a long list of small insignificant rocks.

Newer generations would have had to get up in front of class and name all 200 planets, some grownups believe it or not had a hard enough time remembering all 9 planets. lol

Personally I don't know what to say about this. In a way I still see Pluto as a planet because it is spherical, has a satellite, and is very massive to be a "dwarf Planet" I'll tell you what though, if it is going to be called a dwarf planet, it is without a doubt the largest most complex of them. This decision may be done away with. Astronomers are forming a petition that will try to overturn this new idea.

The scientific reason they demoted Pluto to "dwarf Planet" status, is because it rest in a mass of debre similar to the asteroid belt. I think this decision is a bit Hasty because if Mars were far enough out to be in the asteroid belt would we call it a dwarf planet for this very reason, and cut the number of planets to 7? People are not considering that Pluto is near the size of Mercury, and has its own moon to boot. Obviously it was large enough to be discovered decades ago, unlike other dwarf planets.

Arguably though, Charon and Pluto can be considered as twin dwarf planets, since the common centre of mass is outside both bodies.

Also, if size is used, 2003 UB313 would also be considered as a planet, since it is larger than Pluto, has a satellite, but has a highly eccentric orbit.

If Mars was in the Astroid belt, it would depend if Mars can clear the orbit under its gravity, and possibly gaining a few satellites. I am not sure if there are any research for simulations done on such scenarios.

I believe the definition would not be settled until we look at other star systems and from there, explain features of the solar system (e.g. Why are the inner planets so small compared to the outer planets?)

 

[ArnautDaniel]

They probably did this because they weren't about to classify possibly hundreds of similar sized objects as planets. It would obscure the more important, and well known planets into a long list of small insignificant rocks.

Newer generations would have had to get up in front of class and name all 200 planets, some grownups believe it or not had a hard enough time remembering all 9 planets. lol

Personally I don't know what to say about this. In a way I still see Pluto as a planet because it is spherical, has a satellite, and is very massive to be a "dwarf Planet" I'll tell you what though, if it is going to be called a dwarf planet, it is without a doubt the largest most complex of them. This decision may be done away with. Astronomers are forming a petition that will try to overturn this new idea.

The scientific reason they demoted Pluto to "dwarf Planet" status, is because it rest in a mass of debre similar to the asteroid belt. I think this decision is a bit Hasty because if Mars were far enough out to be in the asteroid belt would we call it a dwarf planet for this very reason, and cut the number of planets to 7? People are not considering that Pluto is near the size of Mercury, and has its own moon to boot. Obviously it was large enough to be discovered decades ago, unlike other dwarf planets.

It is an interesting concept, I believe its a matter of opinion in the case for Pluto in that it is very small to be a planet, and has a wild orbit that follows a heap of debre. On the other hand it is very complex and over sized to be a Dwarf Planet.

I believe the other reason for demoting Pluto was that they have found something bigger than it in its region, and were expecting to find more such bigger objects.

 

[silvermoon383]

Ever since I heard the news about Pluto I’ve been trying to find a way to explain how the new definition of ‘planet’ is bunk. It took me almost a week but I finally got it!

The third part of the definition is that a planet must have cleared its orbit, meaning that nothing else crosses it. This led to Ceres and Xena being dropped from the running because they’re in the Asteroid and Kupier Belts respectively. Pluto was then dropped from the list because it crosses Neptune’s orbit.

[FONT=&quot]Now here’s what I realized. If crossing Neptune’s orbit makes Pluto not a planet, then Neptune can’t be a planet for the same reason, Pluto crosses it, so Neptune’s orbit isn’t clear. Then, look at the other 7 planets. How many asteroids, comets, and meteors cross their orbits? Since Earth has other things crossing its orbit, then we can’t be a planet, and Mercury, Venus, Mars, Jupiter, Saturn, and Uranus also can not be planets! If the new definition is applied to the entire system like they want it to, then our solar system has zero (0) planets![/FONT]

 

[mikenet2006]

Ever since I heard the news about Pluto I’ve been trying to find a way to explain how the new definition of ‘planet’ is bunk. It took me almost a week but I finally got it!

The third part of the definition is that a planet must have cleared its orbit, meaning that nothing else crosses it. This led to Ceres and Xena being dropped from the running because they’re in the Asteroid and Kupier Belts respectively. Pluto was then dropped from the list because it crosses Neptune’s orbit.

[FONT=&quot]Now here’s what I realized. If crossing Neptune’s orbit makes Pluto not a planet, then Neptune can’t be a planet for the same reason, Pluto crosses it, so Neptune’s orbit isn’t clear. Then, look at the other 7 planets. How many asteroids, comets, and meteors cross their orbits? Since Earth has other things crossing its orbit, then we can’t be a planet, and Mercury, Venus, Mars, Jupiter, Saturn, and Uranus also can not be planets! If the new definition is applied to the entire system like they want it to, then our solar system has zero (0) planets![/FONT]

lol, thats a trip. I was thinking earlier that perhaps a planet is demoted only if it has a combination of traits.

Like

has erratic orbit,

follows a similar path that rocks and asteroids follow

is as small or smaller than a pluto sized object



Therefore if mars were in the asteroid belt it would still be a planet due to its size.

and if pluto were in a stable orbit it would still be a planet despite its small size. After all mercury is still a planet.

This really doesnt matter much though its just a definition, we still have pluto . That reminds me do they even give dwarf planets real names? Pluto will be the only named dwarf planet if they keep giving other ones code names.

 

[funyun]

Ever since I heard the news about Pluto I’ve been trying to find a way to explain how the new definition of ‘planet’ is bunk. It took me almost a week but I finally got it!

The third part of the definition is that a planet must have cleared its orbit, meaning that nothing else crosses it. This led to Ceres and Xena being dropped from the running because they’re in the Asteroid and Kupier Belts respectively. Pluto was then dropped from the list because it crosses Neptune’s orbit.

Now here’s what I realized. If crossing Neptune’s orbit makes Pluto not a planet, then Neptune can’t be a planet for the same reason, Pluto crosses it, so Neptune’s orbit isn’t clear. Then, look at the other 7 planets. How many asteroids, comets, and meteors cross their orbits? Since Earth has other things crossing its orbit, then we can’t be a planet, and Mercury, Venus, Mars, Jupiter, Saturn, and Uranus also can not be planets! If the new definition is applied to the entire system like they want it to, then our solar system has zero (0) planets!

Pluto crosses Neptune's orbit, but it isn't static. A body clearing its local neighborhood doesn't mean nothing can enter its neighborhood, or that if something does it instantly hurtles towards the planet. It means nothing can enter its neighborhood and be a static presence there.

For example, let's say two comets enter earth's neighborhood. Inexplicably, one of them stops and the other keeps moving. Comets themselves have orbits around the sun, so unless that comet is on a collision course already, it will keep in its orbit. The other comet, however, won't be able to just float near earth forever. Eventually, depending on where it stopped, it will collide with the earth, OR, it will float away and collide with something else (like the sun), OR, perhaps settle into a Lagrangian position.

You'd think that if it were as easy as you had described, someone would have caught it by now, yes?

 

[ArnautDaniel]

C'mon people. Astronomers are doing nothing more than redefining a word for the convenience of working astronomers.

This is a purely linguistic issue, not a scientific one.

The real motivator was that they were starting to find objects bigger than Pluto beyond Pluto, and the sheer number of objects discovered is getting large.

Pluto probably never would have been called a "planet" in the first place, except that there were so few objects known at the time.

 

[Everglaze]

I don't care what the scientists say. Pluto has been recognized for a long time as a planet and has been quite influential for many mediums. It's still a planet in my book, partially for the fact that I'm a fan of it. Pluto is just too "cool."

 

[geocajun]

lol http://jimmyakin.typepad.com/defensor_fidei/2006/09/what_the_plutoh.html

 

[CaptainJeanLucPicard]

C'mon people. Astronomers are doing nothing more than redefining a word for the convenience of working astronomers.

This is a purely linguistic issue, not a scientific one.

The real motivator was that they were starting to find objects bigger than Pluto beyond Pluto, and the sheer number of objects discovered is getting large.

Pluto probably never would have been called a "planet" in the first place, except that there were so few objects known at the time.

I think it would be somewhat cleaner to add "icy planet" to the other classifications of planets that includes only terrestrial planets and jovian planets. The IAU's definition of a planet leaves quite a bit to be desired. Here is the definition of a planet:

A planet is a celestial body that

• is in orbit around the Sun
• has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape
• has cleared the neighborhood around its orbit

My qualm with this definition is that few planets can be considered to be planets with this definition.

The only requirement that all objects considered to be planets pass is the second one, as they are all nearly round. However, the first requirement excludes all extrasolar planets as they aren't in orbit around the Sun! The final requirement excludes Earth and Jupiter (perhaps others) as planets. Many near Earth objects are documented, and Jupiter is accompanied by a group of asteroids called trojan asteroids that share its orbit.

 

[funyun]

However, the first requirement excludes all extrasolar planets as they aren't in orbit around the Sun!

Are you serious with this? That's because they're defining planets in our solar system. In other solar systems you can substitute "the sun" for "its respective star(s)".

The final requirement excludes Earth and Jupiter (perhaps others) as planets. Many near Earth objects are documented, and Jupiter is accompanied by a group of asteroids called trojan asteroids that share its orbit.

Your confusion results from a misunderstanding of what "clearing the neighborhood" means. It means any object permanently residing in a body's orbit will either suffer accretion, disturbance, or will come under that body's gravitational influence.

The Trojan asteroids do share Jupiter's orbit, but they are at Jupiter's L4 and L5 points, as defined by Jupiter's gravitational influence. Therefore they are precisely the kind of thing that is meant by "clearing the neighborhood". There are similar asteroids for Mars and Neptune.

As for Earth, what objects are you talking about? There are none. As has been addressed elsewhere, comets and meteors are not subject to the rule as they are only temporary visitors, and objects like Cruithne are, like the Jupiter Trojans, under earth's gravitational influence.

 

[horuhe00]

There had never realy been a definition of "planet" and that is why Pluto was considdered a planet 70 odd years ago. I'm content with this outcome. Much better than suddenly having 13 or 16 or whatever number of planets with orbits around the Sun in excess of a quarter thousand years.

 

[[serious]]

How can a planet just "become" not a planet. I never saw any sort of event that would reduce pluto to non planet status. [/flat earth]

 

[ArnautDaniel]

How can a planet just "become" not a planet. I never saw any sort of event that would reduce pluto to non planet status. [/flat earth]

It was partially consumed by Galactus the Eater of Worlds.

 

[SuperSaint4GodDBZStyle]

I really hate that they did that to Pluto. I'd rather have 9 planets than 8 in the solar system. They should have voted on it with the whole world than just that particular group of scientists.

 

[Apollonian]

How can a planet just "become" not a planet. I never saw any sort of event that would reduce pluto to non planet status. [/flat earth]

The "event" that you are talking about has been happening over the last 5 to 10 years.

Astronomers have discovered hundreds of objects of the same class as Pluto in nearly the same orbit around the sun. Why aren't these hundreds of other objects then called planets? Why not have 132 planets in the Solar System...oops we missed one, make that 133...?

The other issue is that over the last 10 years, scientists have been discovering more and more extra-solar planets. This has been changing much of the very nature of what we consider to be a "planet".

The point of the decision of the International Astronomical Union's decision was to define what a "Planet" is in comparison with a "Dwarf Planet" (Pluto) so that scientists could talk intelligently about recent discoveries.

So far, the only reasons that I have heard for keeping Pluto's "Planet" status have been for historical or economic reasons rather than scientific ones. (This of course is excluding the Astrologists who are absolutely inflamed by the decision!)