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Why Is Neptune Still A Planet?
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Steve,<br />I've addressed this issue previously.<br />It is a straw man.<br />Textbooks are obsolete before they are published, in this time. From writing to vetting, to publishing is years, which means in these times obsolete.<br />Whatever $10's of millions you complain about, the textbooks need to be written again no matter what.<br /><br />Do you want me to bring in the previous posts that have addressed these questions, which you have ignored?<br /><br />Actually I will. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
The only scientific purpose of calling something a planet (or a star, moon or comet) is so people know the type of object you are talking about. But there is no rigorous definition of a planet and it really is not so important if an object happens to be somewhere between a planet and an asteroid — or somewhere between a planet and a star.<br />Recent discoveries of hundreds of objects in the outer part of the solar system has opened a planetary debate. These objects are thought to be part of a large collection of Pluto-sized and smaller bodies, that form a disk-shaped cloud beyond Pluto's orbit called the Kuiper Belt. <br />There may be more planets than the usual nine, if we count the larger asteroids and the possibly thousands more Pluto-sized objects in the distant Kuiper Belt that have not been discovered. But just because Pluto is small that does not mean it is not fundamentally a planetary body. <br />Scientists classify the planets into groups. For example, Earth, Mars, Venus and Mercury comprise the "terrestrial planets," which are mostly rocky objects. In contrast, the "gas giant" planets, which include Jupiter, Saturn, Uranus and Neptune, are dominated by thick, molecular hydrogen atmospheres. Pluto and Charon seem to be part of a third category called "ice dwarfs" — they have solid surfaces but, unlike the terrestrial planets, a significant portion of their mass is icy material (such as frozen water, carbon dioxide, nitrogen, methane or carbon monoxide).<br /><br /><br />A Planet: <br /> 1. orbits the Sun (rather than a moon that orbits a planet)<br /> 2. is big enough so that its own gravity pulls it together into a sphere (it must be round) <br /> <br />Its not that clear that pluto isnt a planet, the thing can be reclassified yet.<br />Talking about the orbit, may be because neptune orbit is a bit similar to those of the other planets but in case of pluto the orbit is very different. Also it is similar to the bodies out of the solar system(So called 10th <div class="Discussion_UserSignature"> <strong><font size="2"><p align="center"><br /><img id="a9529085-d63d-481e-9277-832ea5d58917" src="http://sitelife.space.com/ver1.0/Content/images/store/9/2/a9529085-d63d-481e-9277-832ea5d58917.Large.gif" alt="blog post photo" /><br /><font color="#339966">Oops! this is my alien friend.</font></p><p align="center"><font color="#ff6600">╬→Ť╠╣є ’ M€ ’<br />╬→ Ðôŵņ2Ëãřŧĥ ๑<br />╬→ ЙДm€ :Varsha<br /></font></p></font></strong> </div>
<font color="yellow">Obviously the imperfect structure of the Solar System disproves the Intelligent Design theory.</font><br /><br />Obviously Intelligence is impefect, otherwise they would be bored to death (literraly).<br /><br />Intelligent person?: "I have no more problems to work on. No problems for me and no games (because all games have problems). What should I do now with my intelligence??? <waits for an answer and dies due to fixed power consumption levels />"<br /><br />Conservation of energy means that a planet-size computer with planet-size calculations cannot run for very long. Thermodynamic WORK is necessary to perform caculations. An absoulte rule of the universe forbidding planet size computers with planet-sized calculations (beat that wolfram! j/k)<br /><br />To prevent it from losing energy it keeps within itself it must have zero acceleration with respect to everything else outside of it. Zorry, no kan do.
Personally, I would reject any definition that allows Pluto to be a planet, but excludes Luna. Either the Earth-Luna system is a binary planet, or Pluto is not a planet.<br /><br />The previous best definition that one of two objects orbiting a common center of gravity is a moon if the center of gravity is inside the other allows Charon to be part of a binary planet, but excludes Luna. This is to me unacceptable.<br /><br />Although arbitrary and subjective, failing to get Luna classified as a planet, I would seek a definition that excluded Pluto.<br /><br />Dale LaRoy Splitstone
From back when this discussion was active:<br /><br />Here is a revised listing of the largest objects in the Solar System (other than the Sun, which is 99.87% of the Solar System It includes those larger than 475 km in diameter, to limit it to less than 50. It only includes objects in a solar orbit, satellites are excluded. Data is current as of September 14, 2006, with sizes beyond Pluto from the latest MPC data as of Aug 28th. <br />We have accurate diameter measurements for the terrestrial planets, and Pluto. The Gas Giants (pGG), and the Gas Mediums (pBG) are the diameters to 1 bar pressure. <br />These are from the RASC 2002 Observers Handbook. <br />The size for everything beyond Pluto are ESTIMATES, making a number of assumptions. They are not precise, but there are enough of them to get a feel for the statistics. They probably are not off by more than +/- 50%. <br />The mass for everything beyond Pluto is estimated using the density of Pluto (since nothing is known for more distant objects, and most asteroids,) and is displayed here compared to earth. Again, these are estimates, but should not be off by much more than a factor of 2. <br /><br />Name= Common name of object. <br /><br />Disc Desig= Discovery designation using the current system. Where there is none, I have included Planet or Asteroid to make the post easier to read. You have no idea how difficult that is. It's the reason for all the dots in this post, but is much easier to read than the first Pluto Perspectives, Part 1. <br /><br />MPC # = Minor Planet Center small solar system object number, up to and including Pluto, # 134340. Again, for objects without one, I have written something here for readability. 00000 means none has been assigned. <br /><br />Class= General type of Object. <br />The first four are just my attempt to categorize the planets. When you look at the data, it is clear that there are 4 two member groupings, or 2 four member groupings. They don't mean too much, other than my attempt to gr <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
More bad news for Plutophiles.<br /><br />Eris confirmed as 27% more massive than Pluto.<br /><br />I may have to redo the chart above, when I examine the data.<br /><br /> link <br /><br />"<br />Updated: 1 hour, 8 minutes ago<br />WASHINGTON - Pity poor Pluto, the puny former planet is facing yet another indignity. Demoted from planethood a year ago into a new category of dwarf planet, it now turns out that it isn't even the biggest one of those"<br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
<blockquote><font class="small">In reply to:</font><hr /><p>In my opinion, there's too much useless screaming and yelling about it's "demotion". To me the facts speak for themselves, and I have my opinion as to it's "planetary" status, but it changes nothing about it's value. That seems to be a point that all the hysterical defenders of both points of view have missed. <br /><br />It is, and will continue to be a fascinating object worthy of it's upcoming investigation.<p><hr /></p></p></blockquote><br /><br /><br />I agree, but the mere fact that the argument exists, that there was controversy over the definition, and indeed that astronomers felt an "official definition" was needed belie that point.<br /><br />The truth is, humans are hierarchichal beings and as such we do rate where things are in a hierarchy and judge them accordingly worthy or worthless. It's not so long ago that asteroids were routinely referred to as "vermin of the solar system". People care a great deal about categories, and make value judgements accordingly.<br /><br />So, for instance, a dull dirtball like Mercury gets visited by spacecraft because it's a Planet, whereas Ceres for isntance has been entirely ignored because it's "just an asteroid". It may be a very interesting world, but nobody's bothered to look.<br /><br />It's the way people think in all things in life. The more highly rated a thing is the more they care about it. That's why the demotion, which it was in the opinion of just about everybody, mattered. That was why there was the whole debate in the first place, and why the IAU had to hand-craft a definition with little real scientific basis that carefully included all the traditional planets but excluded ice dwarfs.<br /><br />I remember saying this in a pervious thread here- the primary matter was keeping Earth at the "top table"; i.e. in the top category, simply because we live here, despite there being no sense in that at all scientifically. Other than the Sun, there are 4 major solar system obje