[meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
Hi Listees I love to read Sterling K. Webb's posts because they are so informative in an often unconventional way. I love to read Martin Altmann's because they make me smile! Buckleboo to all! Mike Fowler Chicago Can you imagine, what could happened if CIA is monitoring your mail? Soon your president would announce a plan for a mission to Ceres for for for mining Cereals Before the Chinese will do so. ...I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on Ceres and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important in the long-range exploration of space; and none will be so difficult or expensive to accomplish. We choose to go to Ceres in this decade and do the other things, not because they are easy, but because they are CRISPY! Buckleboo the axis of knevil. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
to be a differentiated rock/ice body, and its axis is roughly upright, like a planet, 5 to 10 degrees. Ceres' surface is warmer than a bare body would be and it seems to have both a thin atmosphere and frost. So, only three traditional asteroids are in the running for planet-hood. Ceres is a Plutonian planet; Vesta is a Terrestrial planet; Hygeia, we don't know about.) Let's face it: politics is involved. The French are proud of LeVerrier for Neptune; let's forget that Vulcan idiocy. Is the US going to give up good old Clyde, the only American discoverer of a planet. My guess is NO! The discoverer of Ceres, Giuseppe Piazzi, thought his discovery was a comet! After months, he lost it behind the Sun. He sent his observations to other astronomers and gave up, not interested in a lousy comet. The next year, the great mathematician Gauss tested his new method of calculating an orbit on these odd observations, and he sent his calculation to two German astronomers, von Zach and Olbers (he of the paradox) who re-discovered Ceres AND announced it as a PLANET, which Piazzi never did. Thenafter, Ceres triggered the formulation of the Bode Law (which isn't really a law, it turns out, or is it?). It is interesting that Ceres was a planet for more than 50 years before it was dumped from the roster and left on the bench. It was just over 50 years from discovery that folks began to whisper about Pluto not really being our kind of planet. Most of the many discussions on internet astronomy boards about the meaning of planet are, I discover, fairly irrational. (The stupidest reason I found to be given for demoting Pluto from planet status, by the way, was that Pluto was boring...) I found therein numerous suggestions that ANY body composed largely of ice (40% or 50%) cannot be a planet, regardless of size, a view that oddly enough, seems to be echoed by many professionals in the field, a truly odd view, considering the large number of planet- sized bodies which ARE. Which brings us to that odd KBO, the big one that ISN'T round... 2003 EL61. It is not an ice body; it is not even a rock/ice body. It is a ROCK body, solid rock, like the Earth or Mercury or Venus or Mars. It has two moons (that we know of). If it were our neighbor, we would call it a Terrestrial planet without a second thought... except for one little bitty problem. You see, it's as big as Pluto... one way. But the other way, it's only 1/4 th as big as Pluto! That is, it has an equatorial axis that is four times the length of the polar axis, and another equatorial axis that is 2-3 times the length of the polar axis. That can only be described as Truly Weird. I know what we should name it: PANCAKE WORLD! How can it be called a planet if it's a damned pancake? Well, it's dynamically distorted. It had to be formed hot, molten just like the rest of the Terrestrial planets, but it was spinning so fast that it cooled and froze into the pancake shape. The puzzling thing is not the shape, but the question of how a hot molten Terrestrial body could have formed in the near- absolute-zero environment of the far outer Solar System? Perhaps it formed in the inner system like the Earth but got thrown out. Could the rapid revolution (a four-hour day) be the result of an immense orbit-changing collision? Maybe it's our long lost brother world... Another problem is that the term minor planet has been used for a century for the 100,000 asteroids! This pretty much renders it useless for the job of distinguishing big and small planets from each other, which we would prefer was a gentle distinction. As usual, the history of a terminology is completely entangled in the problem, to the extent that simple direct terms can no longer be used. Minor vs. Major? Planetoids vs. Planets? Planetinos vs. Planets? Because of sensitivity about terminology, the attempt to avoid saying what you meant creates a tangled spate of utterly silly and ridiculous terms, carefully disguised as highly technical and inoffensive language: KBO's, TNO's, not to mention Cubebinos, Plutinos, Two-tinos, SDO's --- Argh! Stop! Stop! How is that making things better? We all know what IAU will do. Nothing. Smart guys. Sterling K. Webb - - Original Message - From: Ron Baalke [EMAIL PROTECTED] To: Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Monday, February 06, 2006 1:25 PM Subject: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate http://www.newscientistspace.com/article/dn8681-xena-reignites-a-planetsized-debate.html Xena reignites a planet-sized debate Maggie McKee New Scientist 06 February 2006 The heated debate over what constitutes a planet has reignited following last week's confirmation that the most distant planet-like object object ever seen in the solar system is larger than Pluto. But astronomers tasked with settling the issue say the argument could
RE: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
Hi Sterling and List, The definition of a planet that I've encountered that I like best is pretty scientifically concise and simple: Any natural body orbiting a star that has a mass greater than the sum of the masses of all other objects in a similar orbit. The only fuzziness in the definition has to do with interpretation of the words similar orbit. Clearly there is a lot of variation in orbital parameters within the main asteroid belt, and among trans-Neptunian objects. But assuming similar isn't overly precise, Ceres would probably not be considered a planet by this definition. While Ceres is the largest main belt minor planet, it's mass is not greater than the sum of the masses of all other main belt asteroids. Pluto is a little trickier since we only know the sizes and masses of a few of the thousands of plutinos. The four largest plutinos known are Orcus, Ixion, Rhadamanthus and Huya. (Pluto itself isn't a plutino since plutino literally means little Pluto.) The combined masses of these four are only a small fraction of that of Pluto; however, there are estimated to be ~1400 plutinos with diameters greater than 100 km. Is Pluto heavier than all of these combined? Possibly. But if we open up the orbit similarity restriction from plutino to Kuiper Belt Object, then Pluto definitely loses its planetary status by the above definition. --Rob __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
a limit of 2000 miles for the minimum diameter of anything called a planet is like saying only individuals over five feet tall can be considered human beings. It's arbitrary and meaningless. I just love your sence of fairness and humor. Jerry Flaherty - Original Message - From: Sterling K. Webb [EMAIL PROTECTED] To: Ron Baalke [EMAIL PROTECTED]; Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Tuesday, February 07, 2006 4:30 AM Subject: Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
My preferred definition is entirely unscientific: Any of the nine planetary bodies orbiting the Sun that have been traditionally called planets. This includes usage in mythology, literature, and scientific publications. This leaves the IAU free to define any number of new terms to describe bodies orbiting a star. These definitions can take into account size, shape, orbital plane, composition, origin, and anything else that is _scientifically_ relevant. It takes planet off the table completely as a formal term, doesn't create confusion by redefining a term that is already in common usage, and pretty much should eliminate controversy. I expect that the reality is, no matter how the IAU defines planet, the vast majority of the lay public will continue to use the term as I defined it above, meaning that when scientists use the term outside their disciplines, they will need to add qualifications. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Matson, Robert [EMAIL PROTECTED] To: Sterling K. Webb [EMAIL PROTECTED]; Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Tuesday, February 07, 2006 12:39 PM Subject: RE: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate The definition of a planet that I've encountered that I like best is pretty scientifically concise and simple: Any natural body orbiting a star that has a mass greater than the sum of the masses of all other objects in a similar orbit. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
Sterling W. wrote: At this point it is worth noting that the major minor planets (Ceres, Vesta, etc.) and the planet Uranus are naked eye objects. ..planet can be made of chopped liver...it can be a pancake ... Hola Sterling, List, All of this talk about planets is making me hungry. I am sure some rapidly rotating stars out there would be tasty pancakes too, and next time Halley's snow-cone comes by I think I'll have a scoop (please hold the aerogel). Now, who has actually seen Ceres with their buff eye? Please tell me, names dates, facts...especially if they are alive, I want to meet this Cererian eagle-eye, and maybe see if a pinch of Kryptonite to taste in their diet ranks with sprouts. Now, wasn't Ceres actually a distinctly Sicilian AND Neopolitan flavor when it was first named? So I guess any Piazzi planet couldn't be a real planet, and only if it were made of green cheese, could it even be a moon? I'd settle for a theoretically stringy basil mozzarella fabric with oregano, and munch at it comfortably on Vesta, the national capital of the Asteroid confederation, where lots more wanderers are certainly visible than from the supposedly named third rock. Yes, the visible from Earth criterion is precisely as foolish as a geocentric theory for the Universe, in my opinion... Saludos, Doug __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
Chris P. wrote: no matter how the IAU defines planet, the vast majority of the lay public will continue to use the term as I defined it above, meaning that when scientists use I heartily second your proposal Chris on the grounds that scientists, if you could call bureaucrats that, are light years out of their jurisdiction when they try to solve an answer which never quite found the problem it is supposed to solve. If anyone actually hijacks the meaning of the world planet from the will of the people, to limit its use in the name of pseudoscience or to force work to be easier on a lexographer, I would personally reject that broadly. Over zealous lumper and splitter taxonomists in many sciences trying to speciate subjective messes beyond any conceivable scientific use should go out and discover an asteroid or something if they really want to make a name for themselves...not shove down the public's throat what the public already knows. 2 centavos worth. And Vesta is a Planet btw:), at least in the eyes of many beholders... Saludos, Doug __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
- Original Message - From: Matson, Robert [EMAIL PROTECTED] To: Sterling K. Webb [EMAIL PROTECTED]; Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Tuesday, February 07, 2006 1:39 PM Subject: RE: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate Hi Sterling and List, The definition of a planet that I've encountered that I like best is pretty scientifically concise and simple: Any natural body orbiting a star that has a mass greater than the sum of the masses of all other objects in a similar orbit. The only fuzziness in the definition has to do with interpretation of the words similar orbit. Clearly there is a lot of variation in orbital parameters within the main asteroid belt, and among trans-Neptunian objects. But assuming similar isn't overly precise, Ceres would probably not be considered a planet by this definition. While Ceres is the largest main belt minor planet, it's mass is not greater than the sum of the masses of all other main belt asteroids. Pluto is a little trickier since we only know the sizes and masses of a few of the thousands of plutinos. The four largest plutinos known are Orcus, Ixion, Rhadamanthus and Huya. (Pluto itself isn't a plutino since plutino literally means little Pluto.) The combined masses of these four are only a small fraction of that of Pluto; however, there are estimated to be ~1400 plutinos with diameters greater than 100 km. Is Pluto heavier than all of these combined? Possibly. But if we open up the orbit similarity restriction from plutino to Kuiper Belt Object, then Pluto definitely loses its planetary status by the above definition. --Rob __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
But Doug, you're irresponsible! Can you imagine, what could happened if CIA is monitoring your mail? Soon your president would announce a plan for a mission to Ceres for for for mining Cereals Before the Chinese will do so. ...I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on Ceres and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important in the long-range exploration of space; and none will be so difficult or expensive to accomplish. We choose to go to Ceres in this decade and do the other things, not because they are easy, but because they are CRISPY! Buckleboo the axis of knevil. Hola Sterling, List, All of this talk about planets is making me hungry. I am sure some rapidly rotating stars out there would be tasty pancakes too, and next time Halley's snow-cone comes by I think I'll have a scoop (please hold the aerogel). Now, who has actually seen Ceres with their buff eye? Please tell me, names dates, facts...especially if they are alive, I want to meet this Cererian eagle-eye, and maybe see if a pinch of Kryptonite to taste in their diet ranks with sprouts. Now, wasn't Ceres actually a distinctly Sicilian AND Neopolitan flavor when it was first named? So I guess any Piazzi planet couldn't be a real planet, and only if it were made of green cheese, could it even be a moon? I'd settle for a theoretically stringy basil mozzarella fabric with oregano, and munch at it comfortably on Vesta, the national capital of the Asteroid confederation, where lots more wanderers are certainly visible than from the supposedly named third rock. Yes, the visible from Earth criterion is precisely as foolish as a geocentric theory for the Universe, in my opinion... Saludos, Doug __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] 2003 UB313 Reignites a Planet-Sized Debate
http://www.newscientistspace.com/article/dn8681-xena-reignites-a-planetsized-debate.html Xena reignites a planet-sized debate Maggie McKee New Scientist 06 February 2006 The heated debate over what constitutes a planet has reignited following last week's confirmation that the most distant planet-like object object ever seen in the solar system is larger than Pluto. But astronomers tasked with settling the issue say the argument could drag on for years. The International Astronomical Union (IAU), responsible for resolving such issues, assembled a special working group to decide on the definition two years ago, when a large new body called Sedna was found in the outer solar system. But since then, several other large worlds have been discovered, including 2003 UB313, unofficially dubbed Xena. This body became widely known as the tenth planet as it appeared to be larger than Pluto, which is about 2300 kilometres across. Now, new results from an independent team appear to confirm this, finding Xena is about 30% wider than Pluto. However, astronomers are bitterly divided over what constitutes a planet. And when the IAU's working group was forced to issue its verdict in October 2005, it failed to find a definition all 19 members could agree on. So it simply reported on the relative popularity of three different proposals - each group member was allowed to vote for more than one proposal. Keeping Pluto A narrow majority of 11 members favoured deeming anything larger than 2000 kilometres a planet. Under this scheme, Pluto would remain a planet and it would be joined by several newly discovered worlds, including Xena. But some group members argued such a size cut-off was arbitrary, set only so Pluto could retain the title of ninth planet. Another option attempted to come up with a scientific justification for a size cut-off. In this plan, planets would have to be massive enough for their gravity to hold them in a stable shape - a requirement that could be met by objects as small as 600 kilometres across. It complicates matters because we get some dozens of new planets, but on the other hand, there's some scientific justification for the size cut-off, says group member Brian Marsden of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, US, who had the idea. In this scheme, which eight group members voted for, all planets would be sorted into four sub-categories based on their location and composition, those being: o Terrestrial planets, such as Earth and Mars o Jovian planets - gas giants such as Jupiter o Cisjovian planets - large asteroids such as Ceres o Trans-Neptunian planets, such as Pluto Another proposal argued that a planet is the dominant body in its immediate neighbourhood. This would demote Pluto, as it is one of several bodies of similar size in the Kuiper Belt - a ring of icy objects beyond Neptune. Six group members voted for this option, which would leave the solar system with eight official planets. Division and discord Because the group was so divided it simply issued a report on its discord, and not a resolution for the IAU's executive committee to put up for a wider vote. That vote would most likely occur at an IAU general assembly meeting, which occur every three years. The next will take place in Prague, Czech Republic, in August 2006. That meeting could see a vote if the executive committee, a representative from an IAU member nation, or one of the IAU's divisions puts forward a resolution on the definition of a planet. But I don't think that is likely given the difficulty the experts had in coming up with a consensus, says Robert Williams, one of 10 members of the IAU's executive committee and an astronomer at the Space Telescope Science Institute in Baltimore, Maryland, US. Williams adds that waiting may also have scientific merit because astronomers have been focusing on defining planets in our solar system, while little is known about the formation and evolution of the 170 or so known planets around other stars. We're trying to define things we don't fully understand, he says. It may be a bit frustrating that we're not quite at the point where we can agree on what a planet is. But the more important thing is a fundamental understanding of what's going on - I would put that as a higher priority than the naming convention we adopt. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
