Make Ceres a Planet?
Personally I have found the whole debate about Pluto's status as a planet a bit depressing. Pluto, and its three known moons, is still incredibly interesting no matter what a whole load of carbon-based life forms on the third planet from the Sun may think. Following Dave P's mention that the state of New Mexico had declared Pluto to be a planet (only when Pluto is in the night skies though), the e-Astronomer points out that "Plutan Officials have so far not reciprocated by recognising the legitimacy of the State of New Mexico". Of course, the e-Astronomer has been suffering the wrath of Pluto-planet-proponents since his part in the re-classification of Pluto last summer but in a shocking turn-around he now wants Ceres reinstated to full planet-status. There is no Ceres petition in place yet (well, there is but it is the wrong Ceres) but no doubt it is only a matter of time.
Comments: Make Ceres a Planet?
Hey. If there's no Ceres petition, You could start one.
Ceres is much easier to spot in a backyard scope. Well, in six months it will be much easier. Right now it's too close to the Sun in the sky. I've seen Vesta, too. Perhaps it's a planet as well.
Posted by Stephen on Monday 26th Mar 2007 (13:56 UTC)
Stuart
now I know you are much more popular than me - my stats have shot up since this plug by you !
Posted by Andy Lawrence (The e-Astronomer) on Monday 26th Mar 2007 (21:55 UTC)
Andy, I don't have that many readers but I'm glad if a few have headed over to your great blog. If you really want your stats to really shoot through the roof you need the Bad Astronomer to make you the subject of a post. With at least tens of thousands of readers he is equivalent to Slashdot for astronomy websites. He linked to one of my posts about a year and a half ago and I got several thousand hits to that page over the course of three days.
Posted by Stuart on Tuesday 27th Mar 2007 (10:14 UTC)
What is really depressing is the political and surreptitious process by which the IAU went about its vote demoting Pluto last year. A lot of people are angry over this and with good reason. The definition is sloppy and is not even accepted by some of the leading planetary scientists in the world, including the co-discoverer of Eris, Dr. David Rabinowitz. The original 12 planet IAU proposal (which included Ceres) makes far more sense and would likely be received much more positively around the world. Those who voted to demote Pluto (424 out of 10,000 IAU members in a hurried process and the last day of the conference) should expect many people around the world to be less than accepting of their decision. Maybe the e-Astronomer is actually having second thoughts on the vote. I for one look forward to it being overturned in 2009.
Posted by Laurel Kornfeld on Monday 23rd Apr 2007 (03:53 UTC)
Laurel, even if all 10,000 IAU members had voted on this issue, I don't think 'the world' would have been happy as the popular opinion is that Pluto is a planet. The point is that most astronomers grudgingly allowed Pluto to be a planet before 2006 for historical reasons, not scientific reasons. The discovery of Eris et al made everyone have to seriously consider it.
Frankly, the details of the original IAU proposal were far from satisfactory and that is why there were almost two weeks of arguments and the resulting compromise. I think you are right that this will come up again in 2009. It may even dominate International Year of Astronomy if people aren't careful.
Ultimately, I don't really care if Pluto is or isn't a planet and don't fully understand why people feel so offended on Pluto's behalf. Being a dwarf planet is not a bad thing. I think everyone gets too hung up on fixed labels.
Posted by Stuart on Monday 23rd Apr 2007 (15:25 UTC)
First of all, the idea that a "dwarf planet" is not a planet at all--specifically stated in the IAU definition--is a linguistic problem in and of itself. The term is an adjective modifying a noun, meaning "dwarf planet" should be considered a subcategory of the larger category "planet." Second, I'm not as sure as you that if all 10,000 IAU members voted, Pluto would still lose its planet designation. The criteria requiring an object to "clear its orbit" is problematic, as it automatically excludes Neptune (for not clearing its orbit of Pluto) as well as Jupiter and Earth for not clearing their orbits of nearby asteroids. The further an object is from the sun, the less likely it will be to clear or even dominate its orbit. And I don't see how the discovery of Eris at all brings Pluto's planethood into question. There is no reason we can't have several subcategories of planets, such as terrestrial planets, gas giant planets, and icy rock/Kuiper Belt planets. Both Pluto and Eris would then qualify as planets, as might many more objects in the region. I do not see any concrete scientific reason to define objects such as Pluto and Eris as anything other than planets. The claim that it would be a problem if we end up with over 100 planets in the solar system is completely unscientific and has to do with convience to us (i.e., people feel it would be impossible to memorize so many planets). According to Dr. David Weintraub, the only qualifications for planethood that can be scientifically defended are that an object orbits a star and is round. All other definitions create artificial, blurry, or arbitrary standards. I very much hope this comes up for discussion in 2009, and I am confident a very different outcome will emerge from the process.
Posted by Laurel Kornfeld on Monday 23rd Apr 2007 (23:25 UTC)
Astronomy is full of bad use of conventions, terminology and dodgy English. Dwarf galaxies are galaxies and dwarf stars are still stars so, for practical purposes, dwarf planets are still planets. Nobody seems to object to the use of 'dwarf' in these instances.
I don't remember David Weintraub (in his excellent book) claiming 'roundness' as a scientific definition, however he did use the related criteria of hydrostatic equilibrium. This definition is better than being 'round' because a quickly rotating body becomes oblate rather than spherical.
Sure it can be debated and re-voted on (with either outcome) but I really don't want Pluto to dominate the whole of the Year of Astronomy. Whether Pluto, Eris, the Moon, Earth or Jupiter are (or are not) labelled 'planets' is semantics and not astronomy. The aim of 2009 should be to inspire the world about the universe and not an endless debate about the name for vaguely spherical lumps of rock, liquid or gas.
Posted by Stuart on Tuesday 24th Apr 2007 (10:23 UTC)
You are correct; David Weintraub does use the criteria of hydrostatic equilibrium. I was using the term "round" interchangeably with "hydrostatic equilibrium," which in restrospect I admit could be considered sloppy.
I think it is a problem that astronomy is full of bad use of terminology and language, one that astronomers need to address. For example, when Ceres, Vesta, Juno, and Pallas were downgraded from full status planets in the mid-19th century, they were given the term "asteroids," which means little stars. They should have been called "planetoids." This may seem like nitpicking but I think it is a problem when astronomers feel they do not have to use the conventions of language employed by the rest of society. Similarly, the IAU resolutions adopted last summer specifically state that "dwarf planets" are not planets at all. This is both confusing and ridiculous and very much needs to be changed.
In attempting to inspire the world and do successful public outreach, it is important to take public sentiment, history, and culture into account. The August 2006 decision demoting Pluto alienated people rather than inspired them. Most people are far more inspired by the adding of new planets than taking one away, especially when that is done based on a flimsy and questionable distinction. It's just my opinion, but I believe astronomers need to be far more in touch with and respectful of public sentiment if they want to be considered approachable and credible rather than perceived as out of touch in their ivory towers.
Posted by Laurel Kornfeld on Tuesday 24th Apr 2007 (22:01 UTC)
Laurel, I think the apparent public/media perception of astronomers in part drove the final decision and partly an angry response to the fact that the media had been told the original proposal before the astronomers (the media reported the story as if it had been passed). You can imagine that to have the world told that your democratic vote was irrelevant might cause anger. Also, in the final voting session (I watched it online) there are comments that if no decision was reached astronomers would be considered a laughing stock. These are not scientific reasons but I think they may have had an impact.
I still think that as a whole, astronomers were not happy with Pluto being a planet. They haven't been happy with it since just after its discovery when it was discovered to be a lot smaller than was initially thought. The opinion is probably different if you just consider planetary scientists.
As I said, I had wanted Pluto to keep its planet status last summer (I'm not in the IAU). That said, I have been very suspicious of the apparent 'public' reaction to the decision (although very few people I know are actually bothered about any of it). Part of this is probably genuine but I think large parts are driven by a media who made a huge mistake announcing the original proposal as if it had been passed. There are also those with an interest in keeping their funding going (especially those with an interest in Pluto or similarly sized objects) so want to keep the topic in the news. In the US I'm sure there is also a feeling of national pride which is partly behind it.
It is very easy to accuse a diverse group of people, from many different countries, covering a wide variety of research, of being in 'ivory towers' or 'out of touch' when they make a decision that you don't agree with. Going off topic a little, I'm always amused when people use the phrase 'ivory tower' as it seems to be solely reserved to attack academic-type people. I've never heard it used to describe plumbers for instance. I wonder where the phrase comes from.
Posted by Stuart on Wednesday 25th Apr 2007 (09:13 UTC)
I'm not saying I view astronomers as being in "ivory towers," but that some members of the public do have this perception. I was and continue to be disappointed in the demotion of Pluto, which I feel did not give sufficient consideration to public sentiment. In a case such as this, where the science does not clearly indicate one view as right and the other as wrong, it is important to recognize that public sentiment is important, partly for successful education and outreach and partly because public money funds most planetary and space missions. If taxpayers feel alienated by astronomers, they will be less likely to support funding for these missions.
Personally, I would have respected the IAU more if no decision was made last summer. There is no reason to rush to a decision if more time, knowledge, and deliberation are needed. I think IAU members perceived they would be viewed as a laughingstock if they made no decision. Again, here is the dichotomy between professional astronomers and members of the public.
I take issue with your statements that those who want Pluto to keep its planet status do so to keep their funding going or because they are motivated by American national pride. Both of these to me are ad hominem attacks because they attack the people making the pro-Pluto arguments instead of addressing those arguments themselves.
As an active participant in the public (not professional) backlash against the IAU decision, I disagree with the claim that large parts of it are being driven by the media. I have been in touch with various groups of amateur astronomers and interested citizens around the world who have mounted grassroots initiatives to reverse this decision, and my experience is that this is a popular movement, not a media-generated one. Some of these groups are in contact with Dr. Alan Stern and other professional astronomers who signed the petition against the IAU decision.
I still do not see why a small planet cannot still be considered a planet. Yes, Pluto is smaller than was thought when it was discovered, but part of that is due to the fact that until 1978, astronomers didn't know they were actually viewing two objects--Pluto and its moon. Eris was originally thought to be significantly larger than Pluto and now is only believed to be marginally bigger. And if, as you state, planetary scientists generally favor classifying Pluto as a planet, shouldn't their views be given greater credence since this particular area is their specialty?
Posted by Laurel Kornfeld on Wednesday 25th Apr 2007 (22:13 UTC)
Laurel, although you say this is a popular movement, my comments stem from the lack of evidence for this amongst people in real life in the UK. I certainly agree that there is lots of chatter on the Internet but I don't think any of the people that have talked to me about this in real life (only a handful of the people I know) are taking it at all seriously. Perhaps the people I know are the wrong type of people.
I am still suspicious of a campaign to 'save' one particular object with very little clamour to re-instate Ceres or to add Eris. Shouldn't these objects also be fully backed? I think they should.
I did not mean to imply that the vested interests of some planetary scientists and US national pride applied to all supporters of Pluto. Anyway, I take issue that these statements were attacks on anybody. Stating possible reasons why some people may want Pluto to be a planet is not to attack them or even an attack on the argument. I did not state that they were invalid or bad reasons. I am merely trying to explore the many reasons behind all this. I am not attacking you, anybody else, or Pluto.
In case this is unclear to anyone reading this, I have no more authority in this topic than anyone else and I have no involvement in, or responsibility for, the current or past status of Pluto.
Posted by Stuart on Thursday 26th Apr 2007 (09:02 UTC)
I wouldn't say you or anyone else knows "the wrong people," just that my experience has been different from yours. I have found that many of the people talking about this on the Internet are also engaged in some form of grassroots advocacy to get last summer's IAU decision reversed, whether through petitions, letter writing campaigns, public forums, or other methods of education and outreach. Not only have I talked about this issue seriously with many people; I've actually made new friends through this effort and traveled from New Jersey to Boston in February to attend a forum that included professional astronomers as part of the Society for the Preservation of Pluto as a Planet's International Save Pluto Day, which was scheduled to coincide with the 101st birthday of Clyde Tombaugh. That event was very well attended.
On another blog, I did state my view that Eris should definitely be given planet status. I have no problem with reinstating Ceres and even some of the other asteroids between Mars and Jupiter that clearly have achieved hydrostatic equilibrium. The reason for the focus on Pluto is specifically objection to its demotion by the IAU. Ceres was not demoted during our lifetime, and Eris never had planet status, so the objection is naturally felt most strongly regarding Pluto.
I appreciate your reassurance that your statements about the vested interests of planetary scientists and American supporters of Pluto were not meant as attacks. I'm always skeptical when people question the motives of those advocating a certain view rather than the points supporting that view. Everyone's motives are mixed to one extent or another, but if someone can prove that an opponent's view is largely determined by a personal vested interest, that damages the opponent's credibility--which is the goal of some who defend the IAU decision (or any controversial position). I'm responding to the fact that on multiple occasions, I've had people use the "American pride" issue, saying it's only Americans who want Pluto to keep its status because Pluto was discovered by an American. To me, this is a weak argument, and I know it is an exaggeration because astronomers from all over the world signed Dr. Stern's petition, and I've personally been in contact with non-American supporters of Pluto's planethood.
Posted by Laurel Kornfeld on Saturday 28th Apr 2007 (04:18 UTC)
Laurel, I'm happy with the scientific case for Pluto. Hydrostatic equilibrium, as you say, seems to be one of the most widely-accepted scientific ways to provide the lower boundary for planet status and I would go with that. What I don't like so much are the "it is too small to be a planet" or "it should be a planet because it was" arguments.
I worry that by focussing most of the effort on Pluto, the outcome will be that Pluto is re-instated but Ceres, Eris and the others are arbitrarily left out. That would be as bad as demoting Pluto.
As you've mentioned already, Pluto could be a sub-class of "planets" and I don't see why "dwarf planet" can't be the name of that sub-class rather than some separate type of object. That way, the usage of "dwarf" would match with all the other areas of astronomy (e.g. stars and galaxies).
Posted by Stuart on Saturday 28th Apr 2007 (11:10 UTC)
I would like to see ceres become a new planet because then it would be more studied.We know more about objects much further away.
Posted by SSG on Tuesday 08th May 2007 (23:33 UTC)
I would like to see ceres become a new planet because then it would be more studied.We know more about objects much further away.
Posted by SSG on Tuesday 08th May 2007 (23:33 UTC)
I would like to see ceres become a new planet because then it would be more studied.We know more about objects much further away.
Posted by SSG on Tuesday 08th May 2007 (23:33 UTC)
I would like to see ceres become a new planet because then it would be more studied.We know more about objects much further away.
Posted by SSG on Tuesday 08th May 2007 (23:33 UTC)