What is called as Kuiper Belt?
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The Kuiper belt is the region of space beyond Neptune. In this region billions of pieces of primordial debris from the formation of the solarsystem resides. They slowly circle around the sun in highly eliptical orbits. Sometimes one of these objects loose some kinetic energy from a collision to put it in an orbit so elliptical it moves into the inner solar system. They then become Comets. More and more planet sized objects are found in this region and makes us ask wheter or not Pluto may actually be a medium sized Kuiper belt object instead of a planet. Otherwise the solarsystem may be getting a whole bunch of new planets.\nThe Kuiper belt streches from Neptunes orbit out to about 0.5 lightyears from the sun. Beyond the Kuiper belt lies another region with billions of "Comets-to-be" called the Oort cloud.
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It is a theoretical planet. There have been numerous reports of finding it. It is most likely the same kind of thing as Pluto, which is an asteroid that gets lightly caught in the suns gravity. They are actually starting to think there are a lot of little asteroids that are "mini-planets" like that out past Pluto.
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The newly discovered planet that rotates our sun is called 2003 UB313, but this question is causing a stir because since theres so many objects that are the size of pluto that rotate our sun scientists are trying to define what the term "planet" exactly means.\nfor more information look at the website below from "NASA"
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According to Wikipedia, the official designation of this "planet" is 2003 UB313.  Its discoverers claim that it is definitely larger than Pluto, and that it has at least one moon.\n\nThe name is not actually Xena, and this is simply a codename used by the discoverers, and has not been submitted to the International Astronomical Union for consideration as a real name for the planet.\n\nIt's roughly 20 percent larger than Pluto, I guess.  They can't disclose the name that they will be proposing for the planet.\n\nThere is a re-definition of the term "planet" going on right now by the IAU, so it is possible that this will turn out not to be considered an actual planet.\n\nMore info here: http://en.wikipedia.org/wiki/2003_UB313
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First of all, it is not galaxy you are talking about, it is solar system. Secondly, a lot of people here are saying why ask such a stupid question. What most of them probably don't know is that while pluto is the smallest of our "officially classified" planets it has come to light in recent months that we may have more planets. \n\nThe debate has been raging on in the space exploration community that recently discovered bodies past pluto may actually be planets in our system as well. They are also saying they may take pluto off the official planet list because it is looking more and more like a captured asteroid compared to these new planets.\n\nFor those who want to read more about these new planets, do a search for the planet Xena (which is the temporary code name for the new planet). \n\nIn short, Pluto is "currently" the right answer but if it is removed from the list, then mercury will be the smallest planet.\n\nHope this helps!
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A Jovian (Juputer-like) planet is another term for a gas giant, i.e. one of Jupiter, Saturn, Uranus and Neptune. Pluto is not a gas giant, and the question should not list it that way. It is a cold lump of rock and ice.\n\nSo the answer to the question "which of Jupiter, Saturn, Uranus and Neptune has the largest axial tilt?" is Uranus.\n\nAnd this what Wikipedia has to say about it:\n\n"Axial tilt\nOne of the most distinctive features of Uranus is its axial tilt of ninety-eight degrees. Consequently, for part of its orbit one pole faces the Sun continually while the other pole faces away. At the other side of Uranus' orbit the orientation of the poles towards the Sun is reversed. Between these two extremes of its orbit the Sun rises and sets around the equator normally.\n\nAt the time of Voyager 2's passage in 1986, Uranus' south pole was pointed almost directly at the Sun. \n\nOne result of this orientation is that the polar regions of Uranus receive a greater energy input from the Sun than its equatorial regions. Uranus is nevertheless hotter at its equator than at its poles, although the underlying mechanism which causes this is unknown. \n\nThe reason for Uranus' extreme axial tilt is also not known. It is speculated that during the formation of the Solar System, an Earth sized protoplanet collided with Uranus, causing the skewed orientation.\n\nIt appears that Uranus' extreme axial tilt also results in extreme seasonal variations in its weather. During the Voyager 2 flyby, Uranus' banded cloud patterns were extremely bland and faint. \n\nRecent Hubble Space Telescope observations, however, show a more strongly banded appearance now that the Sun is approaching Uranus' equator. By 2007 the Sun will be directly over Uranus' equator."
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The Van Allen Radiation Belt is a torus of energetic charged particles (plasma) around Earth, trapped by Earth's magnetic field. The Van Allen belts are closely related to the polar aurora where particles strike the upper atmosphere and fluoresce.\n\nThe presence of a radiation belt had been theorized by Nicholas Christofilos prior to the Space Age and was confirmed by the Explorer I on January 31, 1958, and Explorer III missions, under Doctor James Van Allen. The trapped radiation was first mapped out by Sputnik 3, Explorer IV, Pioneer III and Luna 1. The release of fluorohydrocarbons in the upper atmosphere causes a selective absorption of alpha particles in that space. A conglomeration of such (invisible) clouds are called pseudo–Van Allen belts and are 1x10-9 lower than the real Van Allen belts. Recently, the NSF funded 2 competing proposals to study these belts and their effect on the amount of radiation that enters the inner atmosphere of the earth.\n\nEnergetic electrons form two distinct radiation belts, while protons form a single belt. Within these belts are particles capable of penetrating about 1 g/cm2 of shielding (e.g., 1 millimetre of lead).\n\nThe term Van Allen Belts refers specifically to the radiation belts surrounding Earth; however, similar radiation belts have been discovered around other planets. The Sun does not support long-term radiation belts. The Earth's atmosphere limits the belts' particles to regions above 200-1000 km, while the belts do not extend past 7 Earth radii RE. The belts are confined to an area which extends about 65° from the celestial equator.
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The International Astronomical Union decided that Pluto was no longer a planet. The reason is that while Pluto is round, orbits the sun, and has three moons, it has not cleared (via gravity) its own orbit of debris.  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.
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Yes I have.  They featured an article about it on Space.com and the NASA website.  Seems that many other Kuiper belt objects have mutiple satellites (moons) as well.  It will be interesting what the New Horizon probe will find when it gets out to Pluto and beyond.  I am hoping the launch will be on time so it can use the gravitational assist from Jupiter to get there quicker.  There was a NASA site where a person could get their name placed on a CD that is launching with the probe.  Several of my friends and I signed up and our names are on that disk now.
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Not at all. You are correct the plance you are talking about is called the ecliptic plane.  almost all the planets fall on the ecliptic plane (to within a few degrees anyway, all but pluto but it's not a planet anymore) . You would still have to dodge asteroids, comets and other things by going 90 degrees to the ecliptic but they are fairly rare.
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I'll assume you meant "in the solar system"\n\n -  "pluto" isn't a planet! It's just a big block of dirty ice...\n\n -  The biggest planet is Jupiter, and is made of gas.\n\n -  The smallest would be mercury, which is right next to the sun.\n\n -  It would be hard to say which planet is "medem", since there are really big planets (the gas giants: Jupiter, Saturn, Uranus, and Neptune), and really small ones: (the inner planets: Mercury, Venus, the Earth and Moon, and Mars)
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1.  Pluto, Sedna, Eris, Ceres, etc. are still planets but they are a specific class of planets ("dwarf planets").  This is similar to the Sun being classifed as a "yellow dwarf" but it's still a star.\n\nNow that I've got that off my chest, Pluto and Sedna are members of the Kuiper Belt, a collection of bodies that extend from about Neptune's orbit out to where the Oort Cloud is supposed to begin.  The Kuiper Belt is approximately co-planar with the ecliptic but extends farther away from the central plane of the solar system.  This definition allows Pluto, whose orbital inclination is significantly larger than average to be included in the Kuiper Belt.\n\nAstronomers are consistently finding more members of the Kuiper Belt through photographic review.  Most are smaller than Pluto, Sedna and Eris, some are similar in size and there is likely to be at least one more body that will be larger.
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It is called a large chunk of ice afloat in the ocean:)\n\nP.S or an iceberg
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Well, really, we don't actually have a scientific definition of a planet.  Shocking yes.  Embarrassing even more so.  But we are working on it.  The problem we are facing right now is that we have a large collection of "transition objects" out there, things that sit right on the border of "planet or not."\n\nAt the high mass end, it is pretty clear cut, Things that produce internal energy by fusion are stars, things that don't are planets.  The transition between star and planet thus seems to be at about 12 times the mass of Jupiter.\n\nAt the small end things are muddled because of Pluto.  No good definition of planet exists that keeps only 9 planets.  You can make a definition to include Pluto, but then you must include a lot more objects.  This is where we actually focusing on right now.\n\n"gravitationally round" is thrown around a lot.  My professional opinion is that this one one make the cut.  It seems nice, a planet is a planet because it has enough self-gravity to crush itself into a round shape.  The problem with this definition is that it means we would have about 100 planets in out solar system.  The largest asteroid, Ceres is round, as are most of the icy bodies in the Kuiper Belt.\n\nThe one that seems to be picking up steam is "dynamically dominant."  This basically means that a planet "dominates" the space around them.  Take a look at the area around the earth - nothing else similar to it.  Same with Venus, Jupiter, and the rest. (moons and rings are bound to the planet so they don't count).  Ceres (the largest asteroid) is surrounded by many, many other asteroids.  Same goes for Pluto, it is surrounded by many other icy bodies of similar size (including one that is bigger than it).  This definition leaves us with 8 planets.\n\nReally right now the "planets" are just defined by fiat, they are planets because we call them that and nothing more.  As a planetary scientist I feel a little guilty not being able to actually define one of the words in the name of my field, as such I've honestly been spending far more time working on this whole "planet" mess, than on my own research.
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Its both ways actually-an asteroid and a planet.pluto circles the sun.this is the reason why its called a planet.but it also cuts across the eliptical orbit (if you know what i mean)while the others dont.There was a big debate on what pluto really was.anyway right now i think pluto is considered an asteroid and not a planet.
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Not sure how you want this question answered, but here goes:\n\nThe solar system consists of the Sun, the 10 planets, the asteroid belt, The Kuiper belt, and the Oort cloud. The Sun is a main sequence G2 star that contains 99.86% of the system's known mass. Its two largest orbiting bodies, Jupiter and Saturn, account for more than 90% of the remainder; the Oort Cloud might hold a substantial percentage, but as yet its existence is unconfirmed.\n\nIn broad terms, the charted regions of the solar system consist of the Sun and its planetary system: the eight bodies in relatively unique orbits commonly called planets or major planets and two belts of smaller objects, which can be called minor planets, planetoids, meteoroids, or planetesimals. Pluto, the ninth planet, is also considered a member of the outer belt, and its status is currently uncertain, particularly since the discovery of 2003 UB313 (see below). Most objects in orbit round the Sun all lie within the same shallow plane, called the ecliptic plane, and orbit in the same direction. Many are in turn orbited by moons, and the largest are encircled by planetary rings of dust and other particles.\n\nThe major planets are, in order, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Eight of the nine planets are named after or derived from gods and goddesses from Greco-Roman mythology.\n\nDistances within the solar system are measured most often in astronomical units, or AU. One AU is the mean distance between the Earth and the Sun, or 149 598 000 kilometres. Other units in common use include the gigametre (Gm, one million kilometres) and the terametre (Tm, one billion/milliard kilometres). Pluto is roughly 38 AU (5.9 Tm) from the Sun, while Jupiter lies at roughly 5.2 AU (778 Gm).\n\nUsing radiometric dating, scientists can estimate that the solar system is 4.6 billion years old. The oldest rocks on Earth are approximately 3.9 billion years old. Rocks this old are rare, as the Earth's surface is constantly being reshaped by erosion, vulcanism and plate tectonics. To estimate the age of the solar system scientists must use meteorites, which were formed during the early condensation of the solar nebula. The oldest meteorites (such as the Canyon Diablo meteorite) are found to have an age of 4.6 billion years, hence the solar system must be at least 4.6 billion years old.\n\nThe current theory of solar system formation is the nebular hypothesis, first proposed in 1755 by Immanuel Kant and independently formulated by Pierre-Simon Laplace. The nebular theory has been refined over many years and now has a great deal of evidence supporting it.\n\nTo briefly summarize, the nebular theory holds that the solar system was formed from the gravitational collapse of a gaseous cloud called the solar nebula. It had a diameter of 100 AU and was 2-3 times the mass of the Sun. Over time a disturbance (possibly a nearby supernova) squeezed the nebula, pushing matter inward until gravitational forces overcame the internal gas pressure and it began to collapse. As the nebula collapsed it began to spin faster to conserve angular momentum, and became warmer. As the competing forces associated with gravity, gas pressure, magnetic fields, and rotation acted on it the contracting nebula began to flatten into a spinning protoplanetary disk with a gradually contracting protostar at the center.\n\nGrains of dust (silicates and metals) and ice (hydrogen compounds) condensed from the gas, and began to accrete into larger and larger clumps, forming planetesimals. Inside the frost line, planetesimals were composed of rock and metal, because those are the only grains that can condense at those temperatures, and remained relatively small because they were only 0.6% the mass of the disk. The larger icy planetesimals beyond the frost line became massive enough to capture and hold onto helium and then hydrogen gases, which caused them to rapidly grow into jovian protoplanets.\n\nAft
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many favor the reclassification of the bodies in the solar system into three groups, the rocky terrestrials, the gas giants, and the ice dwarfs.  there are hundreds of bodies that orbit the sun farther than neptune known.  these include bodies like pluto, quaoar, sedna, and 2003 UB313.  this is also called the kuiper belt.  pluto was the first kuiper belt object discovered.