Is pluto a planet?

Question

Im confused....?

Answer 1

http://en.wikipedia.org/wiki/Pluto

no, pluto is not a planet, but pluto does orbit the sun, is ball-shaped and is not a satellite, but it does not have an isolated orbit (a bunch of other similar bodies have similar orbits.) so it is not a planet.

this was the right thing to do, believe me. this does not change anything about pluto or the solar system. this just corrects the mistake of classifying pluto as a planet initially.

i have been waiting for this since i was about ten when i learned that pluto didn't fit the pattern set by the major bodies in the solar system so it was an anomaly. it just felt "out of place". now that astronomers have found hundreds of other bodies with similar orbits, classifying "134340 pluto" as a planet is even more irrational. i feel somewhat satisfied, but i don't know how long this will drag on tho. many planetary astronomers are satisfied that the definition is not rigorous enuff. i can accept that the definition is flawed, but i can not accept that "134340 pluto" is a planet.

this same thing happened has happened before. in 1800, an astronomer found a body orbiting the sun between the orbits of mars and jupiter and thought it was a planet. astronomers finally stopped classifying them as planets in about 1850 after they found several other bodies with similar orbits, and no one thinks ceres, pallas, juno, and vesta are planets today.

incidentally, "134340 pluto" was never a moon of neptune. neptune did capture triton. this is why triton has a retrograde orbit. many astronomers consider pluto and charon to be a binary system, but two small bodies orbit that system. they are called nix and hydra

Answer 2

Is Pluto a planet???? Yes and no...

Well for starters, Pluto is just too small. In the neighborhood where Pluto lives? Planets are supposed to be huge. The Jovian planets, Jupiter, Saturn, Uranus and Neptune are 20 to 300 times the size of the Earth, and Pluto is really small compared to the Earth, smaller than our Moon. Kind of stands out.

And Pluto is not made out the same material as the Jovians. The large planets are mostly gigantic spheres of gas, mostly hydrogen and helium. Likely there are no solid surfaces, only denser and denser gas all the way in. Pluto is a small solid world of methane, water, carbon dioxide and ammonia ices, maybe a little rock and with a just hint of atmosphere (that freezes out and falls as snow in her "winter").

And third, Pluto's orbit is the most eccentric (oval shaped) and the most tilted to the plane that the rest of the planets orbit in. Also, Pluto is locked in a resonance with Neptune's orbit and comes closer to the sun than Neptune sometimes.

There were theories that Pluto was a lost moon of Neptune but that was before we discovered she a has one large moon (Charon) half her size (pretty much, this system is a double planet) and recently two other teeny-tiney moons (Nix and Hydra).

Pluto seems like she cant be an ejected moon-she must have formed on her own and seems to be part of an entire army of small icey-dwarf objects that circle just outside Neptune's orbit in what is known as the Kuiper belt. We have no idea of how many or how large these objects may be, hundreds???? NOT "planets" proper, hence the new term "dwarf planet" where Pluto is king.

But... I still think Pluto SHOULD be called a planet because of historical reasons (discovered by an American, financed by Percival Lowell, Tombaugh's life story, etc).

Answer 3

It depends on what you think. I think scientists should achnolage the other things that we find in our solar system. Isn't Mercury a planet and what about the asteroids and the other cool crap that floats around in space? Even though it maybe considered not a planet, there is more to our solar system than the sun and the planets you know. They are from the outside universe and could tell us a plethura of stuff. There are other "plannetoids" byond Pluto (eg, Qutoar, Sedna, and probobly many more.) The oort cloud extends very far. possibly there is a gargantuine plannet that is holding some very far away in the outer reaches of our solar system. I am surprised that our little sun (yes it is small compaired to most stars. It is a dwarf yellow average.) could hold so much in it's orbit. But I think Dark Matter (Matter making things 2/3rds more massive than they really are that we can't see.) helps a bit too.

Answer 4

All of the people are totally wrong!!!!!!Pluto is the ninth planet in the solar system.Most people think that Pluto is not a planet because its not big enough well i have a question to those people what is Pluto then?PLUTO IS THE NINTH PLANE T OF THE SOLAR SYSTEM!!MOST PEOPLE DON'T KNOW WHAT A STAR IS A GLOWS WITH LIGHT AND A PLANET DOESN'T GLOW DOES IT.

Answer 5

The scientific world or most astronomers have declassified Pluto as a planet,there is however a number of astronomers that are fighting to leave pluto as it was before, a planet

Answer 6

On 8/24/06 the members of the International Astronomical Union (the IAU which governs the naming of celestial objects) voted to downgrade Pluto from a full fledged planet. This was done when other larger objects were found beyond Pluto so instead of calling them all "planets" they were renamed as "dwarf planets."

Answer 7

It used to be widely considered to be the ninth planet, but now we know that there are many objects of similar size orbiting out in the outer limits of the solar system, and if you're going to call Pluto a planet, then they would all have to be planets too. And really all they are is big icy masses, more like planetoids. A system with inner terrestrial planets and outer gas giants seems to make more sense.

Answer 8

Space Topics: Pluto Top Ten Is Pluto a Planet? by Bill Nye



Bill Nye
Vice President, The Planetary Society
In 1999, the International Astronomical Union (IAU) issued a statement declaring that Pluto is a planet akin to ours (Earth...). The IAU did this to address an Earth-wide argument raging among astronomers and other Earthlings about whether or not the distant relatively small object we call Pluto should be thought of as a “planet.” Or, should it be something else, something less significant than, say, our own planet Earth? One might easily dismiss this debate as trivial when compared with global (Earth-borne) terrorism, deadly pandemics, and catastrophic climate change. But, this sort of thinking affects our world or worlds view, if you will.

This argument came about, because Pluto is different. For one thing, its orbit is different. It’s tilted or inclined relative to the orbits of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. That suggests an origin quite different from, say, Mars or Earth. Pluto is small, less than half the size of Mercury. Although Pluto has Charon, a moon almost as big as Pluto itself, they’ve both recently been found to be part of a complex system of remote icy bodies gravitationally tugging on each other, blurring the conventional definitions of moons and solar orbit

Because of the discoveries of other icy bodies out there, like Sedna, Quaoar, and 2003 UB313, all similar in size to Pluto and Charon, it’s likely that if Pluto were discovered today, it would not be called a “planet.”

Either we stop referring to Pluto as a planet, or we reckon this 75 year-old definition with the new discoveries. When Pluto was discovered, “planet” was pretty much the only noun around. But after all, Pluto and Charon do orbit the Sun, and they do have enough gravity to become spherical— cold worlds suspended in the darkness.

The eight traditional planets orbit the Sun in very nearly the same plane, as though they were all sliding on a Solar System-sized invisible tabletop, what I like to call the “Main Plane.” So, we can describe our Earth and the seven others as “the Main Plane” planets.

Then, Pluto and the other icy objects out there would be described with a different modifier. They could be the “Icy Dwarf Planets,” for example. Or how about this, “the Plutonian Planets.” That would be the worlds past Neptune and at least, say, 2000 kilometers in diameter. The IAU and the rest of us can keep calling Pluto a planet (diameter about 2274 km), but we would all just have to get in the habit of referring to these objects as Plutonian bodies to distinguish them from Main Plane bodies.

In astronomy and in science education, we would find ourselves being consistent. We have always added descriptors as we go along. When we refer to planets orbiting other stars, for example, we just add “extra-solar” (separate from the Sun).

This month we’re launching the New Horizons spacecraft to go have a close look at Pluto. Whatever we discover there, you can bet it will be spectacular.

And my fellow Main Planers, I’d bet we wouldn’t be sending this mission, committing all the required resources, if we hadn’t thought of Pluto as a planet since its discovery in 1930. The mission is called New Horizons, because although we know what we’re looking for, we’ve never had cameras up close that far out. We’re not sure what we’re going to find. On to Pluto, the first of the non-Main Plane, icy dwarf, Plutonian planets.

Answer 9

On August 24, 2006, the International Astronomical Union passed the following definition of a planet:

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

Pluto is not a planet, as it fails condition c: Neptune is the gravitationally dominant body in Pluto's orbital neighborhood. However, Pluto does fall under the IAU's definition of a dwarf planet, also passed on August 24, 2006:

(a) is in orbit around the Sun,
(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
(c) has not cleared the neighbourhood around its orbit, and
(d) is not a satellite.

Answer 10

Well, since you and I won't be going there any time soon, it really doesn't matter all that much, does it? It's a big ball of rock with two moons (that we know of) that orbits the sun - I'd call that a planet. Some astronomers disagree. I really can't see why it's all that important what it's called. What the hey, maybe it's just another big asteroid. There are other examples of asteroids with their own moons. I don't plan on losing any sleep over what to call it now that my old acquaintance Clyde Tombaugh has passed away...