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is PLUTO a planet?

hi everyone; I have heard that Pluto is not a planet? anyone heard this? before when i was a student my teacher include Pluto as the last planet but now when i heard it form my son he did not include Pluto in the list of the planet and i said why there no Pluto here? and He said He dont know the Pluto and It was not on the list of his book..

Any new discovery now in Planet Pluto?
Yeah there was some definition war a few years ago or something.

This may interest you:
You could refer to this article.

In short, the mass measured later is smaller, and it is too light to be a planet.
wow! thank you for the information history changes.. nah.. i am getting old.
Pluto is a Dwarf Planet.
Very similar to a planet, but, generally small, and has not cleared its orbital path of debris.
Ankhanu is correct in Pluto being a dwarf planet. Scientists consider Pluto to be the smallest of all the planets, unless any new smaller ones have been discovered lately?
No, Pluto is NOT a planet and there are thousands of bodies smaller than Pluto.
drunkenkoz wrote:
Ankhanu is correct in Pluto being a dwarf planet. Scientists consider Pluto to be the smallest of all the planets, unless any new smaller ones have been discovered lately?

Bikerman wrote:
No, Pluto is NOT a planet and there are thousands of bodies smaller than Pluto.

Quite right. Pluto is NOT a planet, which means it cannot be the smallest planet. It is, as I said, a Dwarf Planet, a separate category of celestial body, and is one of many... and is not the smallest of Dwarf Planets neither.
Since they found other planets besides Pluto and some of the findings were even bigger than Pluto. So instead of adding new planets, they removed Pluto from the list of planets and added it and the others that they found to the list of dwarf planet.
Pluto is not a planet
It is estimated that there are hundreds or even thousands of dwarf planets in the Solar System (see Wikipedia article about dwarf planets). Five are known so far: Ceres, Pluto, Haumea, Makemake, and Eris.

In that sense Pluto really lost the status of being something special when it was demoted in 2006. There are only 8 planets in our solar system. As a cold comfort its name was used to coin the name of a sub-class of dwarf planets, the celestial bodies in orbit around the Sun at a distance greater than that of Neptune: Plutoids.
Well I guess we'll have to accept the fact that it is not a planet due to the supporting facts even though we were taught before that it was .
Pluto is not the first "planet" demoted as more knowledge was obtained. When the first four asteroids were discovered, they were called planets, but later Ceres and the others were recognized to be non-planets and given the new name asteroids. Finally in 2006 when Pluto was demoted, Ceres became a dwarf planet along with Pluto, because it was also one of the larger non-planetary bodies.

Please forgive my weak reference link:

When Ceres was first discovered in 1801, it was classified as a planet. Later, as more asteroids were discovered, it was reclassified as an asteroid. Finally, in 2006 when the category "dwarf planet" was defined, it was reclassified as a dwarf planet. This reclassification was based on its size, twice as large as any other asteroid, and its round shape.
maybe because it also behaves like a dwarf planet. Notice its revolution is different from other planets and it sometimes switch places with neptune. Dwarf planets like ceres also do that. Although the funny part is that pluto, despite of being a dwarf planet, still has a moon (Charon).
I also checked out wikipedia and it say's pluto has 5 moons
I'm not updated about this Smile
no its not a planet was downgraded

Cold rocky and ice in places, there might be life there..... Embarassed
SlashnburnSoftwareStudio wrote:
no its not a planet was downgraded

Reclassified, not downgraded.
Yes, Pluto got "demoted" from planethood status -- something it clearly didn't deserve in the first place, but because we got used to it over several decades it seems sad. Look on the bright side though. Several new bodies also got "promoted" to dwarf planet, and there are probably at least half a dozen more in the kuiper (sp?) belt that will also turn out to be dwarf planets, and even Pluto itself gets more attention than before, now being considered as a possible dual-planetoid system along with Charon, which is way too big to just call a moon of Pluto and leave it at that.

Stay tuned, Pluto, Charon and ensemble is currently scheduled for a family portrait. We'll soon be hearing a lot more about them and their role within the solar system.
Using terminology like "downgrade", "demote", "promote", "upgrade", et al. is very misleading. It only really works when there is a hierarchy, which is absent here. The only reasons to use those terms are sentimental ones and they promote a fallacious idea that there are privileges or other benefits that come with the title/classification. These terms are merely descriptive, nothing more.
No, it's not. Honestly, I think the "protests" against its downgrade a bit pointless.
To be a planet or not to be?

This is one of the many answers:

Is Pluto a planet?
The definition of a planet continues to be debated.
The debate about whether Pluto is a planet was generated
by recent detections of hundreds of planetary objects
in the outer solar system.
The International Astronomical Union classifies Pluto as a dwarf planet.
Most people call Pluto a planet because it orbits the Sun and it is large enough
that its own gravity has pulled it into a spherical shape.

I also call Pluto a planet.
More information is to be found on the Nasa's Missions to Pluto site New Horizons.

New Horizons is a spacecraft launched on January 19, 2006 from Cape Canaveral Air Force Station, Florida.
The first close-up flyby of the Pluto will happend on July 14, 2015.
If Pluto is a planet then obviously Eris must also be a planet since it is larger and satisfies all the other criteria.There are other bodies which would also need to be classified as planets, such as Chiron, for the same reason.
So there is a choice - increase the number of planets to 11,12,13 or more (there are quite a few bodies similar to Pluto in the Kuiper belt) or reclassify Pluto as a dwarf planet. Personally I think the latter choice was correct and sensible.
I really find the whole Pluto planet "debate" curious, and at its core entirely trivial. It's a little like debating evolution with the general public; it doesn't really matter how the general public feels on the subject. How celestial bodies are classified is entirely up to those in the field of astronomy; they define how their words are used and what they mean. Planet is still a word that they're working on nailing down a conclusive definition for, and in that effort, some things that were once considered planets no longer will be, and some that weren't may become. What difference does it make to we on the sidelines?

Why do people care whether Pluto is a planet or not? Is it because when (many) they went to school they were told it was a planet? Is it because it's relatively small, and small things are cute or somehow an "underdog"? If Pluto is a planet, will they trigger some sort of release from suffering and entrance to a state of nirvana?

The whole thing strikes me as one of those pointless crusades that people latch onto emotionally when they're pretending that they "like science", when they truly care nothing for the reality of science, but like to be seen appreciating new technology and flashy sciencey headlines.
Really, if you love science, you'll accept that as science progresses, it changes, especially classifications. New information triggers reexamination of what we once thought we knew, and things adapt to fit all the data on hand. As someone who has a strong interestin in the classification of living organisms, this sort of thing happens <i>constantly</i> as various taxa are revised. What we once thought was a single species turns out to be a complex of several, or the opposite where multiple species are reclassified as a single species... or splits and combinations at higher levels... we don't cry about it, we embrace the change and enhanced knowledge it represents.

Put the "debate" to bed... unless of course, you're part of a committee that is officially concerned with the classification of planets and planetoids.

Horizon just sent us picture. Yes is is planet Very Happy
if its not a planet then what else it can be?

If You're Still Arguing About Whether Pluto Is a Planet, You're Missing the Point
It's time to get past old semantics arguments and realize that our solar system is full of amazing objects we should visit.

take a look:
urielt wrote:
if its not a planet then what else it can be?

A Dwarf planet, obviously... since that's its current classification Wink

urielt wrote:
If You're Still Arguing About Whether Pluto Is a Planet, You're Missing the Point
It's time to get past old semantics arguments and realize that our solar system is full of amazing objects we should visit.

Quite true. A label is just that, a label. The change in classification does not change what Pluto IS, just what we call it... which, ultimately isn't very important. Planet, dwarf planet, oversized mote of dust... whatever we call it, it is what it is, and it's beautiful.
Nasa’s historic New Horizons mission to Pluto has revived those passions, if not the official debate.

On the other side of the ring is New Horizons lead scientist Alan Stern, who said in 2011 the IAU had “embarrassed” itself and that under the definition used Earth would sometimes not be a planet.

I think it is classed as a Dwarf planet at current but not an actual planet.
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