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Space

Giant Asteroid Breaks 200 Year Old Record 179

Renobulus writes: "The BBC has this story about a giant asteroid orbiting near Pluto. This article also talks about Pluto's role as a planet in our solar system. This asteroid could help prove scientists belief that Pluto is only a minor planet."
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Giant Asteroid Breaks 200 Year Old Record

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  • I've always personally considered Pluto to be considered more of a general, miniscule satellite of the solar system rather than a real planet. Just because object x isn't where all the other object x's are, doesn't mean said object is not, truly, object of the x variety. It's an asteroid, just not where it should be...I think that when it was finally seen in 1930, someone just got a little excited over finally glimpsing the (at the time) infamous 'Planet X'
    • by Pxtl ( 151020 )
      Actually, by estimites of its composition and its known location, it is considered by many to be the solar system's biggest comet. It is located in the cometary belt, and it is constructed like a comet. It doesn't look like one just because comets do not form a coma and tail until they pass within Saturn's orbit.
      • There is no cometary belt. There is the Kuiper Belt, proposed source of short-period comets, and the Oort Cloud, source of long-period comets.
      • Actually, the tail is created when the core object passes by the sun. The coma -IS- basically the primary object/body...I've never heard of anything involving Saturn...perhaps just my stupidity?
        • I think he meant that the tail isnt really formed until around when it passes Saturn... that the sun's effect isnt hot enough to effect it until around there.
    • They have seen Planet X with the Hubble, it's more the size of Jupiter though!

      The Search for Planet X [xfacts.com]

  • Anyone remember Josie & the Pussycats? That 60s rock band cartoon that got into a spaceship and were landing on "Planetoids"?

    I always thought Planetoids had more style than Minor Planet.



  • Hmmm... don't let the Canadian astonomers know about it, the record may not be recognized because the precedent [theglobeandmail.com] has been set for moons to be unappreciated and even punnished.

    ;)
  • I think i may have missed something in the article. How does this asteroid prove/disprove pluto being an actual planet?
  • by Angst Badger ( 8636 ) on Saturday August 25, 2001 @06:41PM (#2216922)
    I confess I entirely fail to see the point of the hairsplitting going on over whether Pluto is a "major" or "minor" planet, and I sure hope it's being conducted by privately-paid scientists who don't have anything better to do. It's not as if major and minor planets exist as natural categories, like the distinction between neutrons and protons, or even between housecats and weasels. It's an artificial categorization, and a very vaguely defined one at that: if it were well-defined, settling the debate would be as simple as comparing Pluto's properties to the list of requirements for major planet status.

    Personally -- and I am not an professional astronomer -- I think the qualifications should be these:

    1. It should never have been large enough to ignite nuclear fusion, i.e., a planet is not a star or a stellar remnant.
    2. It should not be orbiting another planet, i.e., a planet is not a moon.
    3. And finally, it should be large enough for its gravity to crush it into a spherical shape.


    Of course, my layman's approach is just as pointless as that of these professional scientists, at least until someone can step forward and explain what use the major/minor distinction has.
    • You should become a professional astronomer. For making more sense than those who are involved in the planet vs planetoid dispute (which I think is silly.) It's classification, not science!

      However, your point (3) is tricky. Whether or not something is spherical (and that's another minefield : how spherical is spherical?) depends a lot on its mass and composition. A massive, but hard chunk of rock is less spherical than a small, squishy ball of dust.

      We can categorize by mass of course. And I don't know why people don't do that...(anybody has any ideas?)

      • We can categorize by mass of course. And I don't know why people don't do that...(anybody has any ideas?)

        The people who would use mass as a deciding factor would just set the mass above or below Pluto's mass to agree with their opinion.

        The way I see it, there are only two possible definitions that would make people happy:
        1.) Tradition says we have 9 planets, and there's no arguing with it.
        2.) Anything larger than Pluto is a planet.
      • We can categorize by mass of course. And I don't know why people don't do that...(anybody has any ideas?)

        Ah, well, you see... We're taught not to judge a book by it's cover. Ever since I was but a wee lad I was taught never to make assumptions or sterotypes about someone just because they were fat.

      • know what ?

        i'm actually laughing after looking at that sig.

        DARN.. can't Lucas keep up with the times ??

      • You should become a professional astronomer. For making more sense than those who are involved in the planet vs planetoid dispute (which I think
        is silly.) It's classification, not science!



        I'm a bit miffed that people think that planetary scientists spend out days sitting around arguing about this, firing off papers and rebuttals to journals and so forth. We don't. There is definately a debate on this issue, but it tends to crop up over drinks or lunch, sort like where people start arguing about which football team will win the Superbowl. It's not something we're really that worried about, and I think we all realize that in due time it will be settled.


        Does this point matter? Actually, a little for two reasons. First, funding. If Pluto is downgraded in status to minor planet, odds are that what money for Pluto studies and a Pluto mission there is will decrease even further. Planets are sexier in budget allocations on the Hill. The second reason is pedagougical. When I teach my students about the different types of bodies in the Solar System, Pluto is by far best categorized with the Edgeworth-Kuiper Belt objects. Trying to classify it as a planet (in the usual sense) leads to questions about how it fits with the terrestrial/Jovian split and, ultimately, confusion.


        Reclassifying Pluto won't change a whit of it's orbit, it's mass, or anything about it. But it will affect how we humans think about Pluto. That is, after all, what classifications are for. Putting in the best spot isn't vital, but it is helpful.

        • I agree with you on why we should keep pluto as a planet for funding issues and pedagogy. Besides I like Pluto :).

          I do not think most astronomers debate on the status of Pluto as much as the media makes them to be. (At least not in this department of astronomy, though we don't do much planetary science.)

          But I think that those who does debate (esp. those who wanted to reclassify Pluto) about it, is really doing science a disservice in putting the limelight on the wrong place. Just look at /., people worry about Pluto is/isn't a planet, and missing the point about how interesting Kuiper belt objects are.
    • The obvious point to the debate is whether or not the solar system has 9 (major) planets or 8. But it doesn't mean much, probably something that gets debated mainly when people are drunk.
      1. It should never have been large enough to ignite nuclear fusion, i.e., a planet is not a star or a stellar remnant.
      2. It should not be orbiting another planet, i.e., a planet is not a moon.
      3. And finally, it should be large enough for its gravity to crush it into a spherical shape.
      Pretty reasonable. It would mean that the asteroid Ceres (and probably some of the other larger asteroids) would qualify.
    • Personally I agree for the most part with your rules of thumb. I am at best an amatuer astronomer, but I do have some friends in academia who do this stuff professionally.

      It seems that it might be worth also considering how a given object was formed. For instance I expect my planets to form in orbits around the sun. If they formed as someone else's moon or even remains from some other solar system, I'm not sure I'd think of that object the same way. (Some people think Pluto may have once been a moon of Neptune.)

      Mass is also an important characteristic, but mass is dubiously hard to measure unless something can be observed orbitting the object in question. This is a large part of the reason people spend more time worrying about size.

      Ultimately we need classification that means something, be it mass, roundness, whether the gravitational collapse released enough heat to start a liquid core, or whatever is useful. Until we have a larger sample of planets (afterall there are only 9 we can examine with any detail), I don't think we'll be able to say what the important characteristics are.

      To my mind the debate about Pluto boils down to whether we think it's a rarity. If there are in fact lots of similarly sized asteroids or whatever hiding out there beyond and around Pluto, then Pluto probably isn't all that significant in understanding our solar system.
    • by Anonymous Coward
      Define "spherical". The asteroid Ceres is supposedly roundish. Our friendly visiting comets are also quite nicely spherical.

      Personally I consider the planet/asteroid/comet/planetoid distinction to be completely artificial and uninteresting.

      Crud orbits the sun, from grains of dust to Jupiter sized monsters. Download marvellous Celestia [sourceforge.net] and play with the universe yourself instead (3d card semi-required).

    • Of course, astronomers probably wonder what the fuss is over 'free software' vs 'open source', so the balance of the universe is maintained.
    • The fourth rule (which will probably piss people off more than solve anything) might be to do with orbital paths. For instance, Pluto has a highly elliptical orbit, which looks as though it was ejected from something (like Neptune) or incorporated from something (like the Kuiper belt). Perhaps if you think about the formation of an object, planets are generally assumed to have been a combination of material along a path around a new star in the accretion disk. Therefore, their orbits are more-or-less circular. They're elliptical, but not wildly so like Pluto's.



      Pluto's orbit seems to point to its history either being interrupted by an orbit-changing event like a collision or capture by the Sun. It's possible it was a normal planet to start with, but that seems less likely than the possibility it was just made to look like one by the event. Hence the debate.

      • I do wish that the idea that Pluto is an escaped moon of Neptune would die out. Dynamically, it's neigh impossible to get a moon away from a planet (intact is tougher still) and have it not get reaccreted by the planet. Remember, the orbits must still cross and over a few million years, the smaller body will end up striking the larger!


        Even if you do get Pluto away from Neptune, you have to migrate it's orbit out many AU to it's current location. As of last I looked (last May, for a talk I gave on the Pluto/Charon formation and dynamical evolution), no one knows how you could reasonably do this.


        It is much easier and more reasonable to assume Pluto accreted out of the protoplanetary disk like the other KBOs. Many of them have high eccentricities. Pluto, being in the 3:2 resonance with Neptune, has even more reason to be in such an orbit if you accept the hypothesis that Neptune has migrated outward through the Solar System by about 5 AU. Dynamical studies indicate that Pluto's eccentricity would get pumped up as it moves out with Neptune (being locked into their resonance).

    • " I confess I entirely fail to see the point of the hairsplitting going on over whether Pluto is a "major" or "minor" planet.... I think the qualifications should be these:"

      Does anyone else see the irony in this comment and the ensuing thread?

    • 2. It should not be orbiting another planet

      To say that a planet orbits the Sun, or that a satellite orbits a
      planet is misleading. It is more correct to say that the two
      bodies orbit a common centre of gravity.

      In the case of the Earth/Moon system, the centre of gravity is
      some miles below the Earth's surface. So the moon appears to
      orbit the centre of the Earth. Therefore satisfying point 2.

      In the Pluto/Charon system however, Charon is sufficiently large
      enough, for the centre of gravity to be above the surface
      of Pluto. How does this affect Pluto's classification? It truth,
      it is two "planets" visibly orbiting each other. Is Charon any
      less of a planet simply because it is the smaller than Pluto?

      • To say that a planet orbits the Sun, or that a satellite orbits a planet is misleading. It is more correct to say that the two bodies orbit a common centre of gravity.

        This has been a point ignored and overlloked in many astonomy books. One of the few places I've seen this explaination on a regular basis is in Science Fiction novels. For example, Robert Heinlein was extremely fond of calling the Moon Luna and referring to it as another planet.

        You could make quite a case for the Earth-Luna system being a binary planetary system because of the relative size of the two. Luna is only about 1/4 the diameter of the Earth! If we discovered a binary star system with a similar relationship, we would not hesitate to refer to it as a binary.

        A lot of it goes back to our ancient views of the universe. We got so attracted to the idea that everything circles the Earth that it is hard to let it go. With more obvious examples, we have succeeded, but with a less-obvious example, such as this one, we still maintain this fiction. It is time to let it go.

        grylnsmn
        • The Moon, however, is only 1/81 the mass of the Earth due to its lower density. The center of mass of the system is within the Earth's surface and much, much closer to Earth than to halfway between. Also, if you accept the standard formation model, the Moon is more easily thought of as a moon of Earth and not a planet unto itself. Ditto Charon, incidently.
    • Poster lists three criteria for planethood:
      1. It should never have been large enough to ignite nuclear fusion, i.e., a planet is not a star or a stellar remnant.

        I like this one as is

      2. It should not be orbiting another planet, i.e., a planet is not a moon.

        Oooh - this is tougher - define "orbiting". Asimov once made a very nifty argument based on the fact that the Moon's orbit is convex everywhere with respect to the Sun, so it is it's own planet (so we, Earth/Moon) are a double planet.

      3. And finally, it should be large enough for its gravity to crush it into a spherical shape.


        Short of a nuetron star that is not spinning, and maybe not even then, spherical is way too restrictive. Just use a mass requirement and let gravity and rotation do the rest.


      Now, to the real driving force for these sorts of discussions -- too many graduate students with too few thesis topics.
    • And finally, it should be large enough for its gravity to crush it into a spherical shape.

      As someone else pointed out, how round is "sphere"? Even Earth isn't a perfect sphere.

      I think a better qualification would be...

      Is it's orbit stable? And if so, does it share it with other objects?

      If it's one of a many rocks in a steady path around the sun, it's obviously an astroid belt.

      If it's just a big chunk of rock making a circular voyage, let it be a Planet. It's not hurting anybody.
    • Another criteria for being a planet, IMHO, is that its gravity influences other established solar system bodies. Remember that Pluto was discovered because of the perturbations in the orbit of Neptune that suggested "something is out there".

      Pluto passes the test of being significant enough to perturb a bona-fide planet.

      -AD
  • The record it broke was in size.


    From the article: European astronomers confirmed on Friday that a distant object seen circling our star near Pluto had broken a 200-year-old record.


    The previous incumbent was the asteroid Ceres which was discovered in 1801.

  • "People who believe that Pluto is just a minor planet will have more proof now"

    The article says that, but then fails to say exactly what that proof would be. So, we have a big asteroid orbiting Pluto. How does prove or disprove Pluto's planetary status?

    • Re:Proof...? (Score:2, Insightful)

      by Izmunuti ( 461052 )
      Suppose they next discover a trans-Neptunian object that is larger than Pluto. At that point we'll either have to define this new object as a planet or demote Pluto to minor planethood. I guess it's not really proof but it seems that the more and more objects we find comparable to Pluto in size and in nearby orbits the weaker becomes the case for Pluto remaining a planet. Kind of like how Ceres, Vesta, Juno and Pallas all lost their ~50 year-old planethood when hordes of asteroids began to be discovered back in the 1850's.
      • I think the solar system's planet counter is 1 digit only, so if there was another body discovered between neptune and pluto, we would have 0 planets.
    • So, we have a big asteroid orbiting Pluto. How does prove or disprove Pluto's planetary status?

      It doesn't. Another example of silly people being paid undue attention to by sillier media. If astronomy continues in this way, it is in danger of being classified as a social science.

  • Whether we decide to classify it as a 'major planet', 'minor planet', 'planetoid', or 'planitessimal', is irrelevant.

    Whatever Pluto is, it's been that since before life appeared on Earth, and it will continue to be that long after we are gone.
    • Whether we decide to classify it as a 'major planet', 'minor planet', 'planetoid', or 'planitessimal', is irrelevant.


      Exactly. In fact, the situation is a tautology. If people stop squabbling and agree on a word to classify Pluto (it doesn't matter if it's "planet", "minor planet", "flerbage" or whatever), then by definition that word includes Pluto-like objects.


      Pluto itself remains the same no matter what we call it.

      • Defining "planet" isn't done for Pluto's sake. It's done for human beings' sakes. A good classification scheme in greatly helpful in trying to understand things in science. Where we put Pluto affects how easy it is to see the patterns. Pluto doesn't give a fig, of course, but I do. And my students do, as well, when it comes time to study for the test (in as much as a good classification makes it easier to understand and study).
  • by Anonymous Coward
    It's actually a Kupier Belt object, which isn't really an asteroid. It's made up mostly of ice, whereas an asteroid is made up of rock or metal. It is however the largest minor planet

    Open64 [sourceforge.net] - Support the open N64 emulator for Linux!

  • Has the record player really been around for 200 years already? Wow. It's a shame that giant asteroid had to come along and break that 200 year old record. An antique like that should have been on display at the Smithsonian (or at least auctioned off on eBay).
  • by dragons_flight ( 515217 ) on Saturday August 25, 2001 @06:50PM (#2216950) Homepage
    This article [space.com] on Space.com [space.com] has considerably more detail about the asteroid and the techniques used for its discovery and measurement.

    Included in their discussion is a debate about whether it really is the largest asteroid. The measurement of its radius relies on a reasonable, but not well established, guess for the objects reflectivity of sun light. Also some people claim that since objects at that distance are largely ice, that it may not qualify as a true asteroid (i.e. made of rock).

    Astronomers have such HUGE amounts of data collected I'm glad to see that automated techniques are aiding in discovering new objects.
  • OK, I'm not entirely clear where the line between "planetoid" and "asteroid" is drawn (eccentricity of their orbits, perhaps?), but I do recall a while ago hearing that the difference between a planet and an -oid is that a planet is held together by gravity rather than by chemical forces (a ball of individual grains of sand vs. one really big rock). Now, is this a formalized definition, or is it just a good idea that's been suggested to the community?

    Personally, I think that if Pluto can hold down its own atmosphere (that we can discern from way over here), that's a good indication that gravity is holding it together and it should be considered a planet. The big question should be whether or not Jupiter is a brown dwarf.
    • Almost everything is held together by gravity. Including all asteroids, comets etc....

      • " Almost everything is held together by gravity. Including all asteroids, comets etc...."

        Nope. The less massive the object, the weaker the gravitational force it exerts on its parts. If the constituant molecules were held together solely by gravity, once you shrink to a certain size, the random thermodynamic motion of the molecules would cause the object to eventually break apart.

        Gravity works great for massive objects (like our moon), but it's all but non-existant with smaller objects (like you, your computer, a Mack truck, Eros...). There, the molecules are held together by the chemical (electromagnetic) bonds between the individual molecules.
        Asteroids aren't held together by gravity, they are literally one big rock. If they weren't, they wouldn't be cratered because the first impact would be its last. Just like kicking a sand castle.

        Comets aren't held together by gravity, instead they're held together just like all snowballs: ice crystals gluedd together by the surface tension of liquid water. If it were just gravity, they wouldn't survive passing anywhere near the sun. They'd be torn apart during the first pass from steam pockets. If steam can move ships and locomotives massing millions of tons here on earth, it can sure as heck put something into escape velocity on a body where the average man weighs less than ten pounds.
        • Ok. Points taken. My bad.

          One question.

          Stuff formed originally by graviational collapse. So they are initially formed by gravity in the first place. Now, asteroids get peppered by stuff, and breaks up. But eventually, won't these debris just recollapse back into a messy bunch (sans those which has sufficient escape velocity out of the center of mass)?

        • You are correct that tensile strenght (chemical bonding forces) become important in comet/asteroid sized bodies. But gravity is still the key player. Recall that many asteroids and comets are thought to be little more than debris piles losely held together. Chemical forces can't hold these together, since the rocks that make them up aren't bonded to each other. Gravity, however, can do the job.



          Tensile strength becomes important when you consider tidal forces. A body that is has some tensile strength will be harder to distrupt tidally than a loose rubble pile. (Note that Roche radii are usual considered for gravitially only bonded objects, tensile strength is neglected.)

        • Asteroids aren't held together by gravity, they are literally one big rock.

          Asteroids are held together by gravity... that is why NEAR [jhuapl.edu] could land on one, and why these photos [jhuapl.edu] from the NEAR probe show a boulder field strewn with SEVERAL rocks.

          The limiting factor on how big an asteriod can get without falling apart is a combination of centrifugal force caused by its rotation, and the Roche limit of how far away it is from a larger body that inflictes tidal forces upon it. More on the Roche limit here [umass.edu].

          Comets may be a single cohesive body of some sort, we don't know yet. Hopefully the Contour [contour2002.org] mission will tell us what comets really are made of.

          -AD

      • uh.. no many have gravity that couldn't hold down a sneeze. in fact, many asteriods are held together by their structure (like rock or ice) and not by their weak gravity.
  • Virtual Telescope (Score:5, Informative)

    by Alien54 ( 180860 ) on Saturday August 25, 2001 @07:00PM (#2216978) Journal
    The history of the solar system seems like it was a lot more complex than people have been thinking.

    Pluto is seen as a escaped moon of Neptune.

    Evidence suggests that the Solar systyem underwent major changes about 65 million years ago. The dinosaurs seem to have been minor collateral damage.

    Mars, for example, has a whole bunch of craters that cover just one side of the planet. The other half is pretty clean. Sounds like something went BOOM.

    So oddities like asteroids orbiting pluto etc are par for the course.

    What I find interesting is that The observations were carried out at the European Southern Observatory with the world's first operational "virtual telescope [eso.org]", Astrovirtel [stecf.org].

    - - -
    Radio Free Nation [radiofreenation.com]
    is a news site based on Slash Code
    "If You have a Story, We have a Soap Box"
    - - -

    • Re:Virtual Telescope (Score:2, Interesting)

      by jaga~ ( 175770 )
      Which side of mars is that? are you suggesting the whole exploding 5th planet thing? having craters on half the planet would mean that asteroids chose to strike mars between certain hours every day.. and not during other hours.. I'm not sure why but this doesn't quite make sense to me...
      • Re:Mars Craters (Score:4, Informative)

        by Alien54 ( 180860 ) on Sunday August 26, 2001 @01:44AM (#2217626) Journal
        Which side of mars is that? are you suggesting the whole exploding 5th planet thing? having craters on half the planet would mean that asteroids chose to strike mars between certain hours every day.. and not during other hours.. I'm not sure why but this doesn't quite make sense to me...

        Not a problem. You can search on the string:

        line dichotomy mars craters

        and get all kinds of links at google. The boundary of the crater disparity is at about 35 - 40 degres angle to the equator. There are these links that are interesting:

        * http://www.uapress.arizona.edu/online.bks/mars/cha p12.htm - Part of a book online - describe the conventional view of the dichotomy

        This paper says that the impacts did not take place on a on a repeating basis, but was part of a one time event. Probably 65 million years ago. There are other pieces of the puzzle that tie into this, available from good scientists, on the web.
        * http://www.enterprisemission.com/tides.htm which is from the other side of the fence, but is not badly written.

        There are a lot of PDFs for download as well from many research papers.

        Remarkably, at a June, 2001 Earth Systems Processes Global Meeting in Edinburgh, Scotland, astrobiologist Bruce Runnegar of the University of California in Los Angeles presented some striking independent evidence that "something" major happened in the solar system ~65 million years ago. Runnegar and his colleagues had previously identified evidence of a 400,000-year cycle in ancient ocean sediments, indicating changes in Earth's climate corresponding to natural fluctuations in its orbit. To probe this cycle's influence on Earth's climate over the past 100 million years, Runnegar's team constructed computer models based on known variations in planetary orbits, their proximity to the Sun and their interactive perturbations. In running the models, they found that the known fluctuations of the solar system's dynamics remained constant going back to 65 million years ago. Then, to their surprise, the frequency of perturbations to the orbits of the inner planets suddenly changed

        This was on CNN, etc at the beginning of the summer. Simple searches for "Runnegar" yeild good results on CNN, and in general. for example:
        http://cnn.com/2001/TECH/space/07/05/dinosaur.wobb le/index.html

        - - -
        Radio Free Nation [radiofreenation.com]
        is a news site based on Slash Code
        "If You have a Story, We have a Soap Box"
        - - -

        • Mars has hemispherical asymmetries like Earth's Moon does. Mars's are North/South, unlike the Moon. Planetary scientists are shying away from any explanation involving asteroids peppering the planets only during certains times of day. I saw a wonderful talk by a geophysicist here a year ago where he presented work that indicates that these asymmetries are probably the result in asymmetries in how fluids flow inside the bodies early on. It was quite compelling work,
          • the Moon's dichotomies That I am interested in are along the line of the farside of the moon has far more craters than the near side. which makes sense.

            the dichtomies on mars are not purely North South, but are substantially angled to the equator. This includes the craters distribution, which are of external origin.

            If mars lost all of its water a long time ago (billions of years) then there is an issue. Random distribution is not maintained. Plus some of the crater basins are truly huge (thousands of miles)

            If it lost the water more recently, then this non random distribution is easier to explain. Other anomalies can be explained by internal mechanics, but the crater distribution cannot.

            • The martian is asymmetry is refered to as a north/south one. The craters are externally created, but your conclusion that that implies the asymmetry is externally driven is false. Internal processes wipe out craters. A more geologically active northern hemisphere will result in fewer craters in that hemisphere. Supporting this is the point that the age of the southern highlands is around 4 billion years old, making them as old as the Moon's surface. So the southern hemisphere has simply not been resurfaced, unlike the north.



              You might want to note that most of the impact cratering on any body occurred in the first billion years of the solar system's existence. So I don't see how losing the water billions of years ago has much affect on the asymmetries.

              Now, if you can explain why the near side of the moon should have gotten hit by impacts less than the far side, do tell. I've heard a few explanations, but they all break down on closer examination. If the asymmetry is in fact interally generated, the Moon would then be twisted around to align one face towards the other due higher order gravitational torquing. So it ise that this explaination makes the most sense to many of us.

      • As Khan exclaimed in ST2,

        "*THIS* is Ceti Alpha 5!!"

        Sorry... offtopic...
    • So oddities like asteroids orbiting pluto etc are par for the course.

      Asteroids farther than Pluto are not oddities, but they were in fact *predicted*, and not observed only because it was difficult.
      In the last years, increasingly powerful instruments have started to found a lot of objects beyond Pluto. The surprise is that there are many objects in the 200-300 km range, and some even bigger (like this one). It wasn't expected.

      As the telescopes get more powerful, expect a *lot* more asteroids being discovered farther and farther from the Sun. It is believed that the Oort Cloud (where most of the comets come from) extends for something like 100.000 UA (1 UA is the Sun-Earth distance, or 150.000.000 km. So 100.000 UAs are 15.000.000.000.000 km, roughly 1.5 light-years).

  • No doubt that infernal vagabond is dancing about with his flower and his bauble, singing songs about volcanoes and baobab trees... I say leave the little wretch where he is, so we can all sleep without distraction!
  • One of many (Score:3, Informative)

    by meckardt ( 113120 ) on Saturday August 25, 2001 @07:05PM (#2216991) Homepage

    This article was also on CNN.com [cnn.com] and Space.com [space.com] yesterday as well, to name a few.

    Ceres has a diameter of about 950 kilometers (590 miles), and is still (and always will be) the largest main belt asteroid. This new object, known as 2001 KX76 (representing its discovery year and code), is a member of the Kuiper Belt. Kuiper Belt Objects are the primitive remenants of the prestellar cloud that formed our solar system. They have been expected by planetary astronomers for years, and in the last few years, hundreds have been found, although this is the largest found to date (excluding Pluto). It is anticipated that hundreds of thousands more might be found as better telescopes are constructed.


  • IANAA (I am not an astronomer), so I'm curious about the precise definition of terms such as "minor planet". The article takes the position that the discovery of this new, rather large asteroid somehow supports the position that Pluto is not a "minor planet", not a "regular planet".

    In most things related to the sciences, terminology is used only when a precise (or relatively so) measure is attached to it. What's the defition of a minor planet after all?

    • I'm not an astronomer either, but I suspect that part of what makes a planet a planet is its orbit. All the planets orbit the sun in the same plane and the same direction, because they were formed from eddies in the original dust cloud. I guess this means you could also say that what makes a planet a planet is also its method of formation. There is also a definite ratio between the radii of the orbits of the planets, pointed out by some astronomer about a hundred years ago or so, but I don't think it is part of the definition of a planet, just an intersting property that all currently known planets have.
      • The ratioes (aka, the Titus-Bode Law) break down, actually, around Uranus. It's an interesting rule, but probably more a result of small number statistics.

  • I was hoping for evidence of time-travel and fantasy worlds: I misread the headline as

    Giant Breaks 200 Year Old Asteroids Record
  • by istartedi ( 132515 ) on Saturday August 25, 2001 @08:59PM (#2217213) Journal

    They Will Never Figure Out If Pluto Is A Planet... until they agree on the definition of a planet.

    I mean, come one, how hard is it really? Mass and orbital excentricity. Pick two arbitrary numbers out of a hat. Problem solved. OK, OK, this might allow a gas cloud so you need a density factor, and you ought to limit the furthest approach too (a large body that passes by is not a planet).

    The bottom line here is that it is not really rocket science to come up with a definition for "planet" and stick with it. Why do otherwise intelligent people insist on playing what is, in essence, a semantic game?

    • Because the definition affects how we think about things. That's the point of such classifications: to make thinking about things easier. As we learn more, we discover that our old classifications were naive and sometimes misleading. Remember stars "OBAFGKM"? Did you ever wonder why they are in that order? Because originally they were ABCD..., but that scheme turned out to obscure what was really at work, so it was modified.


      Unfortunately, in astronomy, information trickles in. We can't go and disect a planet or watch it form to figure out how to best classify it.



      What amazes me is that the general public get's so huffy and indignent at the idea that these classifications might require adjusting. They accept that voting boundries, definitions of "adult" and speed limits change, but not that how we classify Pluto. Weird.

  • by bill.sheehan ( 93856 ) on Saturday August 25, 2001 @09:33PM (#2217265) Homepage
    Personally, I think the best part of the article was the masterful self-control displayed by Lars Lindberg Christensen, who responded to the reporter's mind-numbingly stupid question by reassuring him that there's "no apparent danger" that the earth would be hit by this asteroid and waited until the reporter had left the room before convulsing in derisive laughter.


    Just in case, though, we'd better send Bruce Willis...

    • Personally, I think the best part of the article was the masterful self-control displayed by Lars Lindberg Christensen, who responded to the reporter's mind-numbingly stupid question by reassuring him that there's "no apparent danger" that the earth would be hit by this asteroid and waited until the reporter had left the room before convulsing in derisive laughter.

      This reminds me of the press conference after Mickey Mantle's liver transplant. One of the doctors mentioned that the same donor had also provided a half-dozen other organs.

      One of the reporters asked if it would be possible to speak with this donor.

      The doctor managed to summon enough composure to respond with the zinger, "You're a sports reporter, aren't you?"

    • He could have responded like Charles Babbage:
      On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.
  • 'Mr Christensen said there was no "apparent danger" that it could ever collide with our planet.'

    .... this guy must be british.
  • Next year I hope it tries to break it own record. Good luck to you spacerock!
  • The article said that as a Kuiper Belt object, this rock must be given "a mythological name associated with creation."

    May I suggest..."God"?

  • by jayhawk88 ( 160512 ) <jayhawk88@gmail.com> on Sunday August 26, 2001 @05:34AM (#2217854)
    Giant Asteroid Breaks 200 Year Old Record

    When word came down from the Elias Astromony Bureau about the record, orbit was halted, and a small ceremony was held at the perihelion to recognize the achievement. Relatives of Asteroid 195-G6, the previous record holder who fell into Jupiter in 1965, were in attendence to offer their congratulations, as well as several diplomats from the Oort Cloud. The asteroid was presented with a plaque commemerating the event, and took a lap around Pluto's equator for the crowd.

    Said the asteroid after the orbit, "It's nice to be recognized, but to be honest, I'm kind of glad it's finally over. Now I can get back to orbiting, which is what I really enjoy. I mean, I'm a giant rock, and I move through space for millions of years. It's what I love."
  • Okay, so if by some fluke we find a big, lumpy asteroid half the size of the Earth in some far off place, we would obviously consider this proof that the Earth is only a minor planet after all.

    Sheesh! "shedding light" on an arbitrary human classification? Let me just yell semantics! and end the discussion right here.


    • It does shed light on Pluto. The problem with calling Pluto a minor planet and a Kuiper Belt Object is that it is significantly larger than the KBOs known today. But as we continue to fill out the distribution of KBOs, approching Pluto's size, we are left with Pluto starting to fall IN this distribution, rather than appearing to be an outlier. The key here is that the KBOs that we are discovering are undisputably KBOs. A new body found to be half the size of Earth would probably be instantly recognized as a major planet, which would do nothing to affect Earth's classification.
      • But as we continue to fill out the distribution of KBOs, approching Pluto's size, we are left with Pluto starting to fall IN this distribution, rather than appearing to be an outlier.


        So if we find a KBO asteroid as big as or bigger than Pluto, we'll call Pluto a KBO minor planet? I mean, this discovery didn't change the characteristics of Pluto itself...

        What if we find something that looks just like Earth in there, and also an asteroid even larger than Earth? (however unlikely) Do we call the Earth twin a KBO minor planet just because there's an asteroid that's larger than it?


        A new body found to be half the size of Earth would probably be instantly recognized as a major planet, which would do nothing to affect Earth's classification.


        Why? Because it's big? Because we don't want to reclassify Earth? What if it's all lumpy and oddly shaped like some asteroids?

        When we have a definition of a set, and we find an object that is either included by our definition but we didn't want it included, or is not included by our definition but we do want it included, there are two logically consistent courses of action. 1) retain the definition, and change the classification of the object. 2) retain the object, and change the definition for the classification. Either one is fine. The decision to go with 1) or 2) is a 100% arbitrary, human decision having nothing to do with the objects themselves. I believe Lakatosh wrote about this, using polyhedra as an example.

        In other words, Semantics!

        IMO, the article should have focussed on "Scientists discover really huge asteroid! This is really cool!" instead of "Scientists change the label they made for Pluto! This is a major astronomical breakthrough!".



        • You're right, the focus of the articles is off. The discovery of a large KBO is interesting, the classification of Pluto less so. But that's the media for you.



          On the other hand, you completely miss my point. When we discover these KBOs there are instantly recognized as such. I know of no disagreement on this point. That fact that the KBOs are starting to look more and more like Pluto leads to the increasing feeling that we've found Pluto's true family.



          If you can find me an asteroid the size of Earth that is oblong, I'll be worried. Basic physics and geology predict a body that large would be made sphereical by self-gravity. Earth's classification would be a minor triffle compared to suddenly not understanding gravity and the physics of rock. If you could, by some miracle, find a body that is of Earth-size and is clearly asteroidal in nature (composition, etc) but also look like a whole lot like the Earth (asteroids don't), we'd have a problem. This is the case with Pluto: compostion and orbit both look more and more like the bodies we classify as KBOs the more of the KBOs we find.



          Pluto has always been outside the classifications of the major planets: it isn't like the terrestrial planets and it isn't like the Jovian. In a sense, our mistake was finding it too soon. If it had waiting until now to be found, we'd have put it in the KBO family without a thought.



          Is the, as you harp on, semantics? Yes. But that doesn't make it moot. As I've said several times in this discussion, what we call things affects how we think about them. Pluto might not care, but people who think about Pluto will. So the issues should be waved away completely.

  • Planets are in orbits set by Bode's Law. If it's not in such an orbit, it is not a planet.
    • Planets are in orbits set by Bode's Law. If it's not in such an orbit, it is not a planet.

      Baloney. Bode's Law is has no theoretical justification, and fails to predict the existance of Neptune.

    • Bode's Law is just an observation and not a "law". It clearly doesn't work for most of the extrasolar planetary systems we've been finding lately, so it shouldn't be used to justify something like Pluto's demotion to planetoid.

      http://www.sciam.com/explorations/052796explorat io ns.html

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