Should Sharon be considered a planet since Pluto is a planet, and is even smaller than it?
94846
First of all, Charon (Pluto's moon) is not bigger than Pluto.\nPluto has a diameter of about 2274 km and a mass of about 1.27 E22 kg.\nCharon has a diameter of about 1212 and a mass of about 1.90 E21 kg.\n\nBut even if a moon is larger than another celestial body, it should not automatically be bumped up to "planet status".\nAfter all, our moon ("the moon") is larger than pluto, but it is not a planet.
2903
I quote : "Two small moons have been discovered orbiting Pluto, bringing the planet's retinue of known satellites to three and leaving scientist to wonder how it could be. ...The moons are catalogued as S/2005 P1 and S/2005 P2 for now. Once they are confirmed, the discoverers will suggest names, to be approved by the International Astronomical Union."\n\nFrom: http://www.space.com/scienceastronomy/051031_pluto_moons.html
141708
Yes. It's actually in our own solar system.  Whether it is a planet or not is the real question.  It is really small.  While bigger than pluto, it is still smaller than the Earth's moon!
1133662
It's current name is 2003 UB313.  It is larger than Pluto.\n\nBut is not yet officially recognized as a 'planet'.\n\nThat may change later this year as the International Astronomical Union (IAU) firms up the definition of a planet.\n\nAt that point, it will probably be renamed.  The discoverers of the object have submitted confidential names to the IAU.  Some people call it Xena or Lila, but these are not official names, and are not among the names submitted to the IAU.  \n\nIt is not 'Planet X' ... this is a generic name for a theoretical large planet not yet discovered.  (Pluto was once thought to be 'Planet X', but it is too small.)  The Planet X theory has been disproven.\n\nSedna is a smaller object (smaller than Pluto), and may also be reclassified as a planet ... but I don't think it's likely.\n\nOne thing is for sure though ... Pluto will not lose its classification as a planet ... astronomers are sentimental too.
745
There are actually several "planet like" objects beyond Pluto in an area called the Kuiper belt that contains thousands of objects that circle the sun.\n\nAt present none of them have been officially recognized as new planets. \nThe discovery of these new planet size objects including  2003 UB313 (nicknamed XENA), Sedna(in 2004) and Quaoar(in 2002 by the same team) have triggered a re-evaluation of the necessary criteria to call something a planet.\n\nIt is likely that this team at Caltech will  discover other objects to be added to the list of potential "planets" in our solar system.\n\n2003 UB313(nicknamed XENA unofficially) is larger than Pluto which leaves officials in a bit of dilemna.  How can they recognize Pluto as a planet and not this object?
389936
Nope.  That's my professional (astronomer) opinon.  Here is why:\n\nPluto is a member of a large collection of similar sized objects that orbit the sun in the same region as it.  This is the same situation that Ceres, the largest asteroid is in.  Pluto was simply the first of these icy bodies to be found, we have since found almost 1000 other objects that share orbital space with Pluto.  Many of them are almost the same sice as it, and one (2003 UB313) is in fact larger than Pluto.\n\nNo good defination of planet exists that allows for pluto to be a planet without admitting about 10-100 other objects in as planets as well, unless you simple state that Pluto is a planet in an ad hoc manner.\n\nThe definition that I generally use in my work is that a planet is an object that has cleared it's orbital space of all other small bodies.  All of the main 8 planets satisfy the criteria.  Pluto, 2003 UB313, Ceres and other small bodies do not.
438002
Senda - smaller than pluto, not a planet.\n2003 UB313 - bigger than pluto, not a planet\n\nThere are lots of objects just like Pluto out there, but right now it is a "planet" and the others are not.  The IAU's Division of Planetary Science is currently working on the whole planet issue, and we are supposed to have some sort of resolution to this issue by august of this year.  It is actually quite a mess over at the IAU right now.\n\nAs far as the universe goes?  We have found almost 200 objects that we call planets, but they are orbiting other stars.
406851
In our Solar System?  Unlikely.  There are a bunch of things orbiting beyond Pluto that are bigger than it that could be considered planets if size were everything... although Pluto is just a large Comet that orbits on the inside of the Oort cloud.  \n\nIf there was anything beyond Neptune of any consequential size, chances are we would have detected it by now.
1107840
Because there are still arguments whether Pluto is actually a planet, "Sedna" is larger than Pluto. But I believe the argument stems from sheer distance from the Sun, it is more of a rogue body.
1103000
They won't, because their orbits are so different. Pluto intersects the solar system's ecliptic, or orbital plane, twice as its orbit brings it "above," then "below" that plane where most of the other planets' revolve -- including Neptune. And, though they are neighbors Pluto and Neptune are always more than a billion miles apart.
112225
The tenth planet is like really great, thanks for asking.  He spins around and around and makes one revolution around the sun about once every several thousand thousand years.  Therefore you might call this tenth planet (he doesn't mind) a chunk of ice, and not really planet-like at all.  But wait, you're saying, Pluto is a chunk of ice and also a planet!  Well, Pluto actually (he's telling me now) doesn't even consider himself a planet, as he's really just a large ice-chunk in the Kuiper Belt.  The tenth planet (we'll call him "Frank", that's what he prefers) is a little peeved that Pluto gets a thousand-brother belt to wear and all he's got is the occasional through-comet.  We can't help you, Frank, I'm sorry.  We're like, a billion miles away.
767889
The International Astronomical Union decided that Pluto was no longer a planet.  Instead, they decided to classify it as a "dwarf planet".\n\nSee the details below.\n\nRESOLUTION 5A\nThe IAU therefore resolves that "planets" and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:\n\n(1) A "planet" [footnote 1] is a celestial body that (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.\n\n(2) A "dwarf planet" is a celestial body that (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 [footnote 2] , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.\n\n(3) All other objects [footnote 3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".\n\n\nFootnote 1: The eight "planets" are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.\n\nFootnote 2: An IAU process will be established to assign borderline objects into either dwarf planet and other categories.\n\nFootnote 3: These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.\n\nRESOLUTION 6A\nThe IAU further resolves:\n\nPluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.
973992
Something less than 400 members of the 10,000 member IAU voted under a veil of assumed authority to downgrade Pluto's status as a planet after they rewrote the rule book. Most of the new criteria they established that must be met in order for an object to be considered a planet is met by Pluto. It orbits a star, it has a moon, and it is generally spherical in shape. The disqualifying new rule was that Pluto has not cleared its orbital path around the sun and there are other objects sharing the same orbit. This would mean that if another object enters or is found to exist in the same orbital path of the Earth, the Earth would not be a planet. The IAU also failed to take into consideration as to whether or not Pluto is in the process of clearing its orbital path and just needs a few billion more years.
118270
There are alot of objects that exist beyond Pluto. Yet, at this point none of these is really large enough to be considered a planet. Check the source link for more info.
23405
There are still 9 according to the latests NASA reports. Although it has been found that there are several other small objects orbiting past Neptune that are similar in make up and size to Pluto- that pluto's categorization of planet will not be changed. That instead a number system is being talked about to go into effect that will number the bundles of pluto-like objects. Though again, pluto would not be changed. (First Source)\n\nIf it weren't for the stubborn desire to keep tradition- Pluto WOULD NOT be considered a planet, it just does not have the characteristics to make it one. But because tradition is very important in this society- Pluto remains a planet for now.
825827
read http://en.wikipedia.org/wiki/Pluto\n\npluto is neither a planet nor a comet.\n\npluto does orbit the sun, is ball-shaped, does not have an isolated orbit (a bunch of other similar bodies have similar orbits.), and is not a satellite so it is not a planet.\n\ni have been waiting for this since i was about ten.  i knew 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.  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.\n\nmany astronomers consider pluto and charon to be a binary system, but two small bodies orbit that system.  they are called nix and hydra.\n\nincidentally, "134340 pluto" was never a moon of neptune.  neptune did capture triton. this is why triton has a retrograde orbit.
822336
read http://en.wikipedia.org/wiki/Pluto\n\ni don't know what you mean by "special", but pluto does orbit the sun, is ball-shaped, does not have an isolated orbit (a bunch of other similar bodies have similar orbits.), and is not a satellite so it is not a planet.\n\ni have been waiting for this since i was about ten.  i knew 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.  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.\n\nmany astronomers consider pluto and charon to be a binary system, but two small bodies orbit that system.  they are called nix and hydra.\n\nincidentally, "134340 pluto" was never a moon of neptune.  neptune did capture triton. this is why triton has a retrograde orbit.