8 planets or 10 ?

Status
Not open for further replies.
D

dougdegraw

Guest
Scientists has recently shown that the newly discover solar body UB313 which has been touted as the tenth planet is larger than Pluto. UB313 looks to have a diameter of about 1,864 miles across, while Pluto is only 1,429 miles wide.<br /><br />The scientific community is still split on what should constitute a planet, let alone if UB313 qualifies. There are those that say if UB313 isn't registered as a planet, then Pluto should also be removed from the list.<br /><br />So what is your opinion:<br /><span method="POST" action="/dopoll.php"></span>
 
D

dougdegraw

Guest
personally I say make it ten and count it as a great day in our history, something else to tell the grandkids about the times we grew up in.<br /><br />We saw a 10th planet get found.<br />We saw the Berlin Wall fall.<br />We saw the birth of the Shuttle.<br />We saw Glasnost.<br />We saw man's first steps on the moon.<br /><br /><br />The results are so far<br />10 - 4<br />9 - 1<br />8 - 1<br />NO - 1
 
K

kmarinas86

Guest
Ceres and other Asteriod Belt objects got away as minor planets, which isn't confusing. We should do the same with the Kuiper Belt. Size is a questionable criteria. The question should be, what word would be an obvious description of the object. Minor planet is the obvious one (minor in both pop culture and size).
 
A

Aetius

Guest
I think we should classify celestial bodies as planets based on the criteria of internal structure (terrestrial, gas giant, or ice giant) and orbit (a planet being a satellite of only the Sun).<br /><br />Truth be told, for all we know another rocky world the size of Mars might have been exiled to the far reaches of Sol's gravitational influence. I'd classify <i>that</i> as a planet in a heartbeat were it to be discovered tomorrow. But 2003UB313? Pluto? These should all be classified solely as Kuiper Belt Objects, as far as I'm concerned. If it's made of ice, no dice. <img src="/images/icons/wink.gif" />
 
M

mikeemmert

Guest
2002 UB313 is the lost moon of Triton. Triton could not have been captured by Neptune without something to carry away some of the energy with which it flew by Neptune. The object which carried that energy away would get catapulted into a high orbit around the Sun.<br /><br />The 2003 UB313/Triton binary formed in the Sun/Neptune Lagrange point L4 or L5. In the other Lagrange point, L5 or L4, Pluto and 2003 EL61 formed.<br /><br />Pluto and 2003 UB 313 are in a special class of objects - Lagrangians - and need to have a category all their own. There are few survivors of that category in today's solar system.<br /><br />I have done several dozen hours modeling the capture scenario for Triton around Neptune. I got the captures and indeed the "Xena" object was easily flung out to 97 AU and beyond in the simulations. However, for 2003 UB313 to have it's present steep inclination of 44 degrees requires a second perturbation by another large object. My investigation into this is ongoing.<br /><br />That object would have to be at least 10 Jupiter masses. If it were over 13 Jupiter masses, it would be a star - a brown dwarf - and being about the age of the sun and powered by relatively scarce deuterium, it would be a dead star - out of fuel.<br /><br />Anyway, if you're interested, I thought those were very enjoyable threads and I'll test the two links above after posting to make sure they work. <br /><br />/*edit*/ they do.
 
N

nacnud

Guest
Have you seen how far out of the ecliptic it is! It's at about 44<sup>o</sup>
 
B

bonzelite

Guest
<font color="yellow"><br />2002 UB313 is the lost moon of Triton. Triton could not have been captured by Neptune without something to carry away some of the energy with which it flew by Neptune. The object which carried that energy away would get catapulted into a high orbit around the Sun. <br /></font><br />in respect to your research into this, which i find fascinating, even if this proves true somewhow, nobody cares. the general public and world respond to "planet." a round world orbiting the sun is a planet. even if it is small. it is an orb. it orbits the sun. it's a planet. not a space rock or comet. or a meso-planet or minor-planet. or endoplanet, or former moon of another moon or planet --nobody cares about these terms.<i> it is a <b>planet.</b></i><br /><br />plus it has a moon. all the better. and then when they discover an even larger KBO, then what? it's not a planet, either? they're only going to find more and more objects that are planet-sized and are round. <br /><br />this is the other thread all over again. a dead horse.
 
M

mikeemmert

Guest
<blockquote><font class="small">In reply to:</font><hr /><p>this is the other thread all over again. a dead horse. <p><hr /></p></p></blockquote>Yeah, but it's in Free Space. dougdegraw put it in Free Space. OK, I'll bite. It might be a way to put the issues that belong in Free Space on the table. And NONE of this has anything to do with W!<br /><br />I think objects should be put in categories that describe what they are. In my opinion, "planet" for one thing has to be a certain size. That can be arbitrary, like 2000km in diameter, which would make Xena and Pluto planets.<br /><br />But their orbit is important, too. Ceres has the orbit to qualify. It was demoted, that's history. I suppose you could blame Vesta for that; being a much lighter color and therefore reflecting as much light as Ceres, it was once thought to be about the same size. Now we know better. <br /><br />Ceres was demoted from planethood because it's Black. Is that fair?
 
S

strandedonearth

Guest
I went for 8 planets. One astronomer proposed that a planet be defined as a body that has most of the mass in its orbital 'slot,' i.e. the rest of the rest of the material in that orbital range combined has a mass less than the planet. This rules out all the asteroids as well as Pluto (as a KBO), but allows the other 8 planets to remain planets. I can buy into that definition. Anything else that orbits Sol and is big enough to be round can be defined as a dwarf planet. The discovery of Pluto can still be celebrated as the discovery of the first KBO, or it can be 'grandfathered' in as a planet until the next generation of kids is raised learning that it is not.
 
B

bonzelite

Guest
<font color="yellow"><br />Ceres was demoted from planethood because it's Black. Is that fair?</font><br /><br />good point, and, no, it's not fair. that was probably a case of politics and timing that it was not designated as a planet. and, yeah, it'd be one small planet. but spheroid nonetheless. <br /><br />i'd stick with the historical Pluto as the threshold size, else they will already have Sedna, Quaoar, and Ceres as planets, as well as perhaps thousands of yet to be discovered KBOs. the opportunity will arise when a very large KBO is found and then what? <br /><br />if we go with 8 planets, then that will be end of planet-hood forever. nothing thereafter will be deemed a planet, even if planet-sized objects are found by the dozens. it seems inappropriate to me to deny further bodies planethood just to protect the inner 8. i don't see the principle for that protectionism so sacred.<i> let the planets come marching in.</i>
 
M

mcbethcg

Guest
10.<br /><br />Reasons? <br />1. I think orb-orbiting-the-sun captures the popular imagination and the popular definition.<br />2. I think astronomy would get a big boost from adding another planet to the pantheon.
 
A

alokmohan

Guest
Poor pluto is is holding job of planet for 70 years.Let it continue.No new appointment now.9 planets,ok?
 
B

bonzelite

Guest
<font color="orange"> <br /><br />Reasons? <br />1. I think orb-orbiting-the-sun captures the popular imagination and the popular definition. <br />2. I think astronomy would get a big boost from adding another planet to the pantheon.</font><br /><br />great ideas. <br /><br />it would be a wonderful lead-in story, as well, to the upcoming revamping of nasa and the manned moon and mars missions relatively soon. great for headlines and politics.
 
H

harmonicaman

Guest
Pluto = Busted!<br /><br />It's logical for revisionist astronomers to demote Pluto to a KBO because as more of these objects are discovered it will become a fait accompli.
 
P

Philotas

Guest
I didn`t notice this thread, dang. Anyway, there are far more planets in our solar system than 10 - I`d say it`s close to 20 with todays discoveries. <div class="Discussion_UserSignature"> </div>
 
D

dougum3882

Guest
Maybe this is a dumb question, but what criteria make a KBO a KBO? Do Pluto and Xena fit these criteria. If so then they are KBO's. If not then they are more appropriately named as planets since at least they don't violate any criteria for being a planet (since there aren't any criteria for being a planet). That's the way I would look at it. If we have no criteria for being a planet, then maybe we have criteria for being a KBO and we can compare to that. If there are no criteria for being a KBO then why is everyone so quick to assume that if they are not planets then they are KBO's since we haven't defined what a KBO is?
 
H

harmonicaman

Guest
This is exactly the question that the IAU (International Astronomical Union) is currently grappling with. Just like asteroids are asteroids, and not major planets; KBO's are just KBO's and not planets.<br /><br />The process for figuring out what is what is called <i>disambiguation</i> and it's a very difficult and subjective exercise. It is always open to revision and various interpretations depending on one's viewpoint.
 
N

newtonian

Guest
dougdegraw - I have no real opinion, like others apparently.<br /><br />This is semantics - or word definitions. <br /><br />One might as well consult Metropolis' Daily Planet!<br /><br />Seriously, astronomer John Matese has published studies (online) detailing evidence by cause and effect of a 10th planet perturbing orbits in the Oort cloud.<br /><br />The mass of this planet would be much larger than Jupiter but smaller than a brown dwarf.<br /><br />So, er, 11 planets was not one of the choices!
 
J

jmilsom

Guest
I am starting to feel that many more may be found in the Kuiper Belt and if the Oligarchic theory of solar system formation turns out to have some basis, many more further out.<br /><br />Thus I think instead of all of this trifling debate over is it a ‘planet’ or not is unnecessary. I believe we should simply add new ‘classes’ of planets. <br /><br />Like Philotas, I believe one day we will all be comfortable with the fact that there are many more planets in the solar system and will think of these in terms of different classes. <br /><br />And I resent the word ‘ object!’ If a person is short, do we call them an object? All the bodies in our solar system are beautiful. Should we debate whether each of the planets in the Kuiper Belt meets the criteria for ‘object’ perhaps we should demote some to KBT’s Kuiper Belt Things.<br /><br />Pluto was the first of the planets of a new class (which Alan Stern fondly calls ‘ice dwarfs’). We have several new contenders to join this planetary class including UB313, Quaoar and EL61 to name a few.<br /> <div class="Discussion_UserSignature"> </div>
 
H

hungrrrry1

Guest
I have stated before, I think orbit should play a large role in determining planet status and an elongated eliptical orbit like Pluto's and "Xena's" would help to disqualify them as Planets and make them KBO's. Now if you want to call Large (300-3000mile Dia) objects that exist with these type of orbits something different like "Lagrangians" as someone stated or other then that would be good. I was told science would prefer to remove ambiguity in the solar system which makes good sense enough to me to classify a few things that are obviously different. Naming everything larger than Pluto in our solar system a planet would one day become ambiguous for sure. Subplanet? Supercomet? Wrecking ball? Snowball?...Someone said "Ice Giant"...that one sounds good to me...sure they may have elements of all type but one thing is for sure...they are frozen! <br /><br />Ice dwarf doesn't make sense unless you identify an ice giant and I would have to say pluto and xena fit that billing...maybe sedna and quoare fit "ice dwarf"?
 
P

Philotas

Guest
I think ice giants is more suitable for Uranus and Neptune, while ice dwarfs fits well for spheroid KBO`s.<br /><br />I think all object that are round should be called planets....<br /><br />When they are roughly circular in shape, they have likely differentiated, may be geologial active and may hold an atmosphere. <br />Yeah, pretty much what makes up a worthy planet. <div class="Discussion_UserSignature"> </div>
 
Status
Not open for further replies.

ASK THE COMMUNITY

TRENDING THREADS