So my very energetic Mother no longer just saw Uncle Ned passing.
Hmmm - My very energetic male cousin just saw Uncle Ned passing Cousin Xavier.
Or not.
Posted by quidscribis (Member # 5124) on :
It's having problems loading...
And I don't have a clue what the rest of your post is supposed to mean.
Just sayin'. Posted by imogen (Member # 5485) on :
You never did planet mnemonics?
It's opening fine for me - hmmm.
Excerpt:
quote: SCIENTISTS are getting set to expand our solar system by adding three new planets, taking the number from nine to 12 and changing what children around the world are taught about our corner of the universe.
The International Astronomical Union, the accepted authority on planetary matters, has recommended to its members that Charon, Xena and Ceres be ratified as new planets, a US newswire service has reported.
quote:The new order of planets going out from the sun would be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon and Xena.
Posted by Eduardo St. Elmo (Member # 9566) on :
Cool! Now each sign of the zodiac can have its own planet...
Posted by Morbo (Member # 5309) on :
This redefinition, if it passes, will lead to more confusion, not less. I hope the IAU votes it down. It seems like the type of commitee drivel that will please no one and serve little useful purpose.
Charon is a moon, how can it also be a planet? There are 7 larger moons than Charon: Earth's Moon, the 4 Galilean Jupiter moons, Titan and Triton are all bigger than Charon. Charon does have the highest ratio of a moon to a planet (about 11% of the mass), but it's still clearly the smaller one. http://ssd.jpl.nasa.gov/?sat_phys_par
quote: The new definition, which states that a planet is any star-orbiting object so large that its own gravity pulls in its rough edges and produces a near-perfect sphere,
Umm, Ceres is 975×909 km, not a near-perfect sphere.
I'm cool with calling Xena a planet, it's pretty big and orbits the sun, not another planet.
I'd also be willing to lock in 8 planets (minus Pluto) or 9 plus anything bigger than Pluto. But calling Charon a planet makes little sense.
Posted by Morbo (Member # 5309) on :
There's also a good mnemonic for star types, from O (hottest and biggest ) to M (coldest and smallest): Oh, be a fine girl, kiss me.
Which actually tells us more about lonely astronomers than about stars. Posted by Orincoro (Member # 8854) on :
Morbo, I think you're right on. Pluto was called a planet for political reasons, because it was the first "planet" candidate to be discovered by an American, among other reasons. Plus, its more likely an escaped moon, as is its own moon.
I would be in favor of an 8 planet chart, including stellar bodies larger than the largest known moon, which orbit the sun on the plane of the ecliptic and in a tight elipse. Pluto has a wierd orbit, is too small, and is probably the closest of dozens or hundreds of similar extra-jovian objects. What happens when we start locating dozens of outer "planets" when they really bare as much similarity to the inner planets as the keiper belt does? What do we call these objects when we start locating them in other solar systems, as we begin to detect planets of less than Jovian mass?
Posted by MightyCow (Member # 9253) on :
I'm all for making Xena a planet, and I think Gabrielle should get one too. She's the cuter one.
Maybe they can rename Ceres.
Posted by KarlEd (Member # 571) on :
quote:Charon is a moon, how can it also be a planet?
The issue is that Charon is no more a moon of Pluto(or less one) that Pluto itself is a moon of Charon, and neither can be said to orbit the other. They both orbit a center of gravity that is in space between the two bodies. It is much more a "double planet" than a planet with a moon.
I don't really care if both of them are "escaped moons". If they orbit the Sun, and not a planet they are disqualified from being "moons" in my book. If our moon somehow escaped Earth orbit and started circling the Sun on its own, I'd be all for reclassifying it a planet.
Furthermore, the new definition states:
quote:"A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."
There is no requirement of "near-perfect sphere". So what if this leads to a hundred other object that fit the definition coming to be called "planets". In what way does this make things more confusing or difficult? Are we afraid school kids are going to have to recite a list of a hundred planets (along with the dozens of other inane activities many of their classes are filled with)? Is there a problem with referring to the "8 major planets" or the "12 inner planets" if you really have a need for some defined limit?
Posted by Bob_Scopatz (Member # 1227) on :
I read that Pluto is being considered the prototype of a new type of planet called a "pluton." The idea is that they will still be considered planets, but that they are in a special class.
Posted by starLisa (Member # 8384) on :
quote:Originally posted by KarlEd:
quote:Charon is a moon, how can it also be a planet?
The issue is that Charon is no more a moon of Pluto(or less one) that Pluto itself is a moon of Charon, and neither can be said to orbit the other. They both orbit a center of gravity that is in space between the two bodies. It is much more a "double planet" than a planet with a moon.
I'm fairly certain that the same thing is true of Earth and Luna.
Posted by Nighthawk (Member # 4176) on :
The newspaper article on this in my area doesn't mention Xena by name, but rather a "12th planet that is yet to be named."
quote:I'm fairly certain that the same thing is true of Earth and Luna
Although both masses do pull upon each other and the "center of gravity" is not the center of the Earth, the Earth has sufficient mass so that that center is still within the planet.
Charon, as I can recall, is half the mass of Pluto, so the effects of gravity are much more dramatic.
Posted by KarlEd (Member # 571) on :
Nighthawk is right. The center of gravity of the Earth-Moon system is well within the space of the parent planet (Earth).
Posted by IanO (Member # 186) on :
Don't tell this guy. He wrote a book called "The 12th Planet" about an extra-solar planet whose inhabitants are the gods of ancient mythologies. Non fiction, that is.
Posted by KarlEd (Member # 571) on :
What exactly would an "extra-solar" planet be? Until the sun goes all red-giant on us, aren't all the known planets "extra-solar"? [Discounting, of course, planets that orbit other stars. I mean, if it orbits the sun in what way is it "extra-solar" that Earth isn't, for instance?]
Posted by HollowEarth (Member # 2586) on :
quote:Originally posted by starLisa:
quote:Originally posted by KarlEd:
quote:Charon is a moon, how can it also be a planet?
The issue is that Charon is no more a moon of Pluto(or less one) that Pluto itself is a moon of Charon, and neither can be said to orbit the other. They both orbit a center of gravity that is in space between the two bodies. It is much more a "double planet" than a planet with a moon.
I'm fairly certain that the same thing is true of Earth and Luna.
Not really, the center of the earth moon system is inside the earth.
Posted by imogen (Member # 5485) on :
quote:Originally posted by Nighthawk: The newspaper article on this in my area doesn't mention Xena by name, but rather a "12th planet that is yet to be named."
According to wikipedia, it isn't actually named yet. The designation is 2003 UB313 - Xena is the nickname given to it by astrologists.
And this will make Flyingcow happy - the nickname for 2003 UB313 aka Xena's moon is Gabrielle.
What I found fascinating was the dual tidal-lock between Pluto and Charon (Both always have the same side facing each other - unlike say, the Moon and Earth where only the Moon is gravitationally locked). ( Wiki ). To me that lends more credence to the twin-planet theory (ie Charon isn't just a moon).
Posted by IanO (Member # 186) on :
I was typing on the fly. I think I used the term 'extra-solar' to mean a planet that is outside our traditionally understood solar system, that still orbits the sun (according to him, every 3600 years). According to Sitchin, when it does come within the traditional solar system, it passes closely to earth and allows the inhabitants of that planet to interact with humans. They 'made' humans by mixing their DNA with Homo Erectus. They are the Nephilim of old. There was a war between the differing gods that culmunated in some kind of nuclear exchange in the middle east about 3600 years ago. Sitchin deducing these 'truths' from ancient Sumerian legends and projecting modern ideas and word definitions on ancient stories and pictures.
Posted by imogen (Member # 5485) on :
... aaaaand I see KarlEd covered that last point long before me.
Ahem.
What KarlEd said.
Posted by IanO (Member # 186) on :
quote:And this will make Flyingcow happy - the nickname for 2003 UB313 aka Xena's moon is Gabrielle.
I find this hilarious beyond words. A relatively short-lived western tv show during the 90's may be immortalized in naming of a planet in our solar system.
Posted by KarlEd (Member # 571) on :
I wonder how likely that is. I mean, the organization who chooses the name will likely be international and surely not made up of a majority of Xena fans. (Or maybe they are?)
Traditionally, planet names (in our solar system) have been taken from Greek/Roman mythology. I'd rather see them take another name from there, or from another mythology (Odin, Thor, etc) before resorting to contemporary fiction.
On another note, I found this tidbit on Wiki in an article on naming conventions:
quote:Starting in 1801, asteroids were discovered between Mars and Jupiter. The first few ones (Ceres, Pallas, Juno, Vesta) were at first considered minor planets and joined the ranks of the planets. As more and more were discovered, they were soon stripped of their planetary status. Pluto was not considered an asteroid, being found very far indeed beyond any then-known asteroid's greatest distance from the Sun.
So, Ceres was already considered a planet at one point, then demoted, and now stands to be re-instated as a planet.
Posted by BlackBlade (Member # 8376) on :
quote:Originally posted by KarlEd: I wonder how likely that is. I mean, the organization who chooses the name will likely be international and surely not made up of a majority of Xena fans. (Or maybe they are?)
Traditionally, planet names (in our solar system) have been taken from Greek/Roman mythology. I'd rather see them take another name from there, or from another mythology (Odin, Thor, etc) before resorting to contemporary fiction.
On another note, I found this tidbit on Wiki in an article on naming conventions:
quote:Starting in 1801, asteroids were discovered between Mars and Jupiter. The first few ones (Ceres, Pallas, Juno, Vesta) were at first considered minor planets and joined the ranks of the planets. As more and more were discovered, they were soon stripped of their planetary status. Pluto was not considered an asteroid, being found very far indeed beyond any then-known asteroid's greatest distance from the Sun.
So, Ceres was already considered a planet at one point, then demoted, and now stands to be re-instated as a planet.
whatever! They used dirty greek/latin mythology because their languages were the language of science. They've had their run, lets use something more contemporary now that we have new planets to name. I should note I am not a fan of using Xena as one of the names. Really Kirk or Picard would make for a better name Posted by Gecko (Member # 8160) on :
Have you ever even watched Xena?
It six seasons, and not a western by any means.
Posted by BlackBlade (Member # 8376) on :
quote:Originally posted by Gecko: Have you ever even watched Xena?
It six seasons, and not a western by any means.
He means western as in produced in the west, not the genre western.
Posted by imogen (Member # 5485) on :
In terms of the mythology-naming: I found this quote from Michael Brown, one of the people who discovered Xena/2003 UB313 very interesting:
quote: "If the object falls under the rules for other Kuiper belt objects, however, it must be named after some figure in a creation mythology. We have decided to attempt to follow that ruling scheme. […] One such particularly apt name would have been Persephone. In Greek mythology Persephone is the (forcibly abducted) wife of Hades (Roman Pluto) who spends six months each year underground. The mourning of her mother Demeter causes the dead of winter. The new planet is on an orbit that could be described in similar terms; half of the time in the vicinity of Pluto and half of the time much further away. Sadly, the name Persephone was used in 1895 as a name for the 399th known asteroid
From Wiki Posted by theamazeeaz (Member # 6970) on :
quote:Originally posted by IanO:
quote:And this will make Flyingcow happy - the nickname for 2003 UB313 aka Xena's moon is Gabrielle.
I find this hilarious beyond words. A relatively short-lived western tv show during the 90's may be immortalized in naming of a planet in our solar system.
Absolutely not. Planetary Astronomers are rather mad at Mike Brown for even promoting the name Xena, since it flies in the face of all the conventions set down by the IAU for naming minor bodies. When the IAU votes to name the planet and its moon, it will not be Xena or Gabrielle.
Posted by starLisa (Member # 8384) on :
quote:Originally posted by IanO: Don't tell this guy. He wrote a book called "The 12th Planet" about an extra-solar planet whose inhabitants are the gods of ancient mythologies. Non fiction, that is.
That's a matter of opinion.
Posted by starLisa (Member # 8384) on :
quote:Originally posted by theamazeeaz:
quote:Originally posted by IanO:
quote:And this will make Flyingcow happy - the nickname for 2003 UB313 aka Xena's moon is Gabrielle.
I find this hilarious beyond words. A relatively short-lived western tv show during the 90's may be immortalized in naming of a planet in our solar system.
Absolutely not. Planetary Astronomers are rather mad at Mike Brown for even promoting the name Xena, since it flies in the face of all the conventions set down by the IAU for naming minor bodies. When the IAU votes to name the planet and its moon, it will not be Xena or Gabrielle.
I don't understand. Xena turned out to be Ares' daughter, no? That makes her part of the Greek pantheon. And Gabrielle... well, do domestic partners count? <grin>
Posted by The Pixiest (Member # 1863) on :
I still vote for Xena and Gabrielle for planet names.
What are the other planets named for but characters from stories? (well, ok Gods people worshiped. Never the less... stories.)
Posted by IanO (Member # 186) on :
quote:That's a matter of opinion.
I meant that he marketed it as non-fiction. Not that it was true. I'm not that stupid.
Posted by Morbo (Member # 5309) on :
I am familiar with the double planet arguement for Charon, but don't find it compelling. All moons, in general terms orbit around the center of gravity of their planetary systems--whether the COG is in the primary or not shouldn't be the defining characteristic of "moonishness".
The mass of Charon is estimated to be between 8% and 15% of Pluto according to a webpage I saw last night, Nasa said 11%. It's clearly the smaller object.
Posted by Nighthawk (Member # 4176) on :
According to Wiki (can't add link because link contains parentheses):
quote:Charon's diameter is about 1,207 km (750 miles), just over half that of Pluto
quote:Charon has approximately 11.65% of the mass of Pluto.
They're rather hard pressed to consider Pluto a planet.
quote:Charon has been a part of the controversy over Pluto's status as a planet. Under the latest proposal, which will be decided on August 24, 2006, the International Astronomical Union may classify Charon as a pluton, officially making Charon a planet. Under this proposal, Charon would be considered a binary planet with Pluto since the two orbit each other around a center of mass that is outside either body.[4] Those who have argued against Pluto as a planet consider the two as the first discovered trans-Neptunian objects.
Personally, yes, I consider Charon a moon. But these science guys know more than I do.
*EDIT*
Pluto's Wiki:
quote:Pluto and its satellite Charon have often been considered a binary planet because they are more nearly equal in size than any other planet/moon combination in the Solar System. Under the aforementioned planet definition proposal, since they orbit each other around a center of mass that is outside either body, they would be officially considered a binary planet system.[2]
Posted by Jon Boy (Member # 4284) on :
Morbo: But if the center of gravity is somewhere between the two bodies, then how do you determine which one is orbiting the other? Traditionally, a moon orbits a larger body. That's not the case with Pluto and Charon.
Posted by fugu13 (Member # 2859) on :
The whole notion of one 'orbiting' the other is just a human-imposed perspective. They both orbit their combined center of mass, neither orbits around the (center of mass of) the other.
However, I do think the colloquial definition of one body orbiting another is most definitely in line with situations where the combined center of mass is within one or the other object.
Posted by Jon Boy (Member # 4284) on :
Notice that I did say "traditionally." Posted by FlyingCow (Member # 2150) on :
Just for the record, even though MightyCow's name is remarkably similar to mine (though he joined the forum five years after I did), we are not the same person.
It's either a remarkable coincidence, or an homage... or an attempt at identity theft.
I'm going with option 1... for now. Posted by Teshi (Member # 5024) on :
I've always had something of the idea that Charon is pushing the definition of moon. In pretty much all the existing textbooks something of that is explained, it's just not very official.
I guess that makes me very accepting of the idea of "Pluto-n-Charon". I actually rather like the idea of our solar system having a double planet. It makes things more interesting.
Posted by Orincoro (Member # 8854) on :
quote:Originally posted by IanO:
quote:That's a matter of opinion.
I meant that he marketed it as non-fiction. Not that it was true. I'm not that stupid.
You DID suggest that the name Xena was after the TV show... Posted by Morbo (Member # 5309) on :
fugu said it well: in any two body system, both orbit around the common COG.
Suppose an new outer system planet-moon combo is discovered. It could be many decades after their discovery before it is definitively determined where the COG is located. What if the COG hovers right at the boundary of the primary? It could even dip in and out of the of the primary's surface as the irregulaties of the primary rotate. Would that make it a moon one moment, and a planet the next?
Would you call it a planet-moon system? A planet with a moon or planet to be determined later? You could have to wait decades to categorize it. Simpler to call the primary the planet (if it's large enough), the other the moon.
[ August 16, 2006, 05:54 PM: Message edited by: Morbo ]
Posted by Gwen (Member # 9551) on :
Pluto is totally a planet. Just because the shape of its orbit is funky doesn't mean it's less of a planet. Uranus' axis of rotation is perpendicular to its plane of revolution around the sun, which is not true of any of the other planets, yet it's still considered a planet. Charon should be a planet too, if it's true that they both revolve around a point outside of either one of them. Just doesn't make sense to call it a moon. And I think it'd be awesome if Ceres and 2003 UB313 were re-classified as planets. Who cares if that makes it harder to list off all of the planets in our solar system? It's hard to memorize all of Jupiter's moons, too, but that doesn't mean we're just going to re-categorize all of the moons but the Big Four as, I don't know, extra-large ring dust or something. Anyone who really wants to memorize the names of the moons of our solar system (all right, it was fifth grade, I had nothing better to do) can just stick to memorizing the major ones; same with the planets. ("And these were the nine historically recognized planets we had before we decided that we should let in more Kuiper Belt objects, class.") And as far as the name "Xena" goes...shouldn't moons be named after Greco-Roman mythological characters also? Yet although we follow that pattern with Ganymede and Io and Rhea, we've also got Titania and Miranda floating around Uranus, which is a little more modern than that. So either scratch Shakespearean names off of the list, or allow a little more pop-culture, darn it! (And if we ever find a planet populated by headless immortal aliens with a light red atmosphere and red trees, I call dibs on naming it "Planet Claire" after the B-52s song.)
Posted by Nighthawk (Member # 4176) on :
Well, not that I'm disagreeing, but Uranus is a bad example for the argument; it's the third largest celestial body in our solar system.
And don't feel bad: I memorized the moons, too. My excuse is 2001 and 2010, though.
Posted by Dan_raven (Member # 3383) on :
Just some deeply scientific notes:
1) Chouldn't we just combine Pluto/Charon into a single planet, that happens to be divided by some space? We could call it, after Pluto--Goofy.
2)What do you mean Xena is fiction. I thought the show was a true portrayal of ancient Greek life.
3)Why not auction off the names of the planets. After all, its all about the Merchandising. If its good enough for the Milky Way and Mars candy bars, its should be good enough for us.
Posted by theamazeeaz (Member # 6970) on :
The problem with the Greco-Roman mythological characters is that the IAU is out of names. Most of the good potential names got used on either Asteroids or moons and they don't feel they can reuse names, especially because the good names belong to the first Asteroids discovered. Nobody in the IAU except Mike Brown wants the names Xena and Gabrielle.
Posted by Morbo (Member # 5309) on :
I don't know why there is so much importance being placed on whether the COG or barycenter is within the primary or not. To me it's extraneous to a moon definition and adds little. The planet is the primary, anything smaller is a moon.
If you're going to upgrade Charon because of it, shouldn't you upgrade Jupiter to a co-star or super-planet? I suspected the COG of the Jupiter-Sun system is outside of the sun's surface, and according to wiki it is:
quote:Sun-Jupiter system: put Sun in position 0, mass = 333,000 Earths. Jupiter in position 778,000,000 km, mass=318 Earths. Center of mass is 742,000 km from the Sun center, 46,000 km outside its surface. As Jupiter does its 12 year orbit, the Sun does a 1.5 million km orbit around the center of mass.
http://en.wikipedia.org/wiki/Center_of_mass#Barycenter Oooh, there's cool animations of various mass possibilities for 2-body systems, including an odd but elegant meshed ellipse orbit I've never seen before!
Posted by Nighthawk (Member # 4176) on :
It's not that they don't want them; they didn't even submit the names "Xena" and "Gabrielle" as options to the IAU.
Posted by Juxtapose (Member # 8837) on :
quote:posted by Morbo: All moons, in general terms orbit around the center of gravity of their planetary systems--whether the COG is in the primary or not shouldn't be the defining characteristic of "moonishness".
Why not? It sounds like a perfectly reasonable method of determining "moonishness". Since we're (and by "we", of course, I mean "they") deciding on a definition, it's going to be arbitrary. The best we can do is set up terms that will lead to the most clarity.
From your arguments regarding Pluto's and Charon's relative masses, should I take it that you think size should play a central in the matter. Why do you think this to be a better definition? Should we have minimal size requirements?
Posted by blacwolve (Member # 2972) on :
quote:Anyone who really wants to memorize the names of the moons of our solar system (all right, it was fifth grade, I had nothing better to do) can just stick to memorizing the major ones; same with the planets.
Sixth grade. Think we might be distantly related? I never imagined that there was anyone else in the world as obsessed with moons as I was.
Posted by FlyingCow (Member # 2150) on :
Can't they just move on to Greek names instead of Roman ones, or possibly Norse or Egyptian or whatever? Why are we stuck with just Roman mythology?
Posted by theamazeeaz (Member # 6970) on :
We need a minimal size requirement because the number of known asteroids is in the five digits. We can't call every ice potato that orbits the sun a planet. Some Astronomers wish Pluto was considered an ice potato- that's where the size thing comes in- big enough not to be a potato is what the new definition says. But Pluto is more than a chunk of ice- it's a chunk of ice with a tenous atmosphere, a nother planet (however small) and two moons.
Posted by Gwen (Member # 9551) on :
Asteroids aren't ice potatoes; that's comets (and there's some rock involved). Jupiter couldn't be a co-star because it's not a star.
I've been following this debate over at Whatever between Jon Scalzi and Scott Westerfield. To quote a (male) comment-er in a thread over there:
quote:Personally I love that the question is all about size. Yes, there are (a sizeable number compared to other fields of) female astronomers out there but it’s still an old mans club. And having old (geeky) men argue about the size of things relating to their importance just makes me all snickering inside.
(hat="snark") Now Jupiter, by Jove, there’s a planet. Big, massive and fully rotund. He’s got a whole bunch of attendants circling around (say, any of Jupiter’s moons named for male Greeks?) paying close attention, circling close, caught in the gravity of the situation. Big Van Alan belts, you betcha, reaching out and caressing those little moons. Now THAT’S a planet, if you know what I mean.
Then there’s this Pluto. Little puny thing. Not exactly on the level, if you know what I mean. Highly irregular. Has these other guys hanging around. You know what they say. (/hat)
I just get a smirk on my face every time I think about that argument. Say, how many of the IAU members drove here using a car with manual transmission?
If you look at size comparisons, the only reason why Earth/Terra isn't just considered a large asteroid has nothing to do with size (compare the terrestial planets with the gas planets, please, then wonder why there's such a fuss over the dwarf planets being so small); it's because we live on it. Very...human-centric.
Posted by B34N (Member # 9597) on :
At least we're still the 3rd rock from the sun.
Posted by Morbo (Member # 5309) on :
I am officially a curmudgeon now. The astronomer who agreed with my points the most on CBS tonight was an ancient bemonocled blustery british blue-blood, Sir Harumps!-a-lot.
Even the aged Bob Schieffer made fun of him.
Posted by Gwen (Member # 9551) on :
Is Minerva taken as an astronomical-body name? 'Cause Athena totally needs her own planet. She's the goddess of wisdom and crafts and she sprung full-grown--with battle armor on--from her dad's head. Tell me that's not awesome. Plus she totally pwned Poseidon when they were competing to see who would get Athens: they were supposed to try to give a useful gift to the citizens of the city, and whoever's gift was more useful would get it named after them and stuff. All the sea god could come up with was a lame salt-water stream. She created the olive tree--food, fire-fuel, and wood all in one. Now that's a mythological character to invite to your birthday party. (Don't bother with Dionysus, he'll throw up on your couch and annoy Apollo with badly sung drinking songs. Trust me.) Err...what were we talking about?
Edited to add: And I'm never attending one of Eris's parties. Her idea of a great party favor is the Golden Apple of Discord--and then making her guests fight over it. Athena and Hera wouldn't talk to Aphrodite for years, and then there's that whole stupid "Who gets Helen" Greek-Troy tiff their Fairest Goddess pageant judge set off. Posted by Tatiana (Member # 6776) on :
Artemis FTW!
Posted by FlyingCow (Member # 2150) on :
A planet named Diana? People would probably associate it more with the Princess than the goddess.
Posted by Magson (Member # 2300) on :
Saw this a few minutes ago and it reminded me of this thread:
quote:Mars and Venus, Sittin' in a Tree K-I-S-S-I-N-G First Comes Love, Then Comes Marriage Then Comes 2003 UB313 in a Baby Carriage
Posted by Morbo (Member # 5309) on :
Posted by Gwen (Member # 9551) on :
Dunno Magson, it doesn't quite scan right...
Yeah, Diana would be cool. All hands for renaming, say, Saturn? (Come on, naming a planet after Chronos and not one after Artemis? Who's cooler? Who's got more myths with her in it (hint from the pronoun there)? Who's an awesome virgin hunter goddess who tricked her dad into letting her not marry? Hello?)
Posted by Hamson (Member # 7808) on :
quote: Nobody in the IAU except Mike Brown wants the names Xena and Gabrielle.
Sounds like you're taking it a little personally there, theamazeeaz. Are you in the IAU?
Posted by Orincoro (Member # 8854) on :
quote:Originally posted by blacwolve:
quote:Anyone who really wants to memorize the names of the moons of our solar system (all right, it was fifth grade, I had nothing better to do) can just stick to memorizing the major ones; same with the planets.
Sixth grade. Think we might be distantly related? I never imagined that there was anyone else in the world as obsessed with moons as I was.
Good luck naming them all now, there are at least 90 of them in the solar system. And there will be too many planets to name as well if we start calling everything a planet instead of a pluton or a planetoid, or an asteroid.
Hmmm. Let's give the same title to:
1. A lump of rock orbiting the sun, close range, tight elipse, good sphere.
2. A giant ball of gas 1,000 times larger than that, with its own 20 or so moons.
3. A rogue moon which moves in and out of the orbits of the gas giants and doesn't exactly follow the plane of the ecliptic, and which, by the way, is one of probably dozens like it.
4. Non-uniform large asteroids which never formed into planets because of the Jovian gravitational influence, having no atmosphere or techtonics, and being a good 1,000th the size of the inner planets.
We should call all these things by the same name?
But hey, I've always thought that Jovian and terrestrial bodies should have different names as well. Jupiter is as like the sun as it is like Earth, and probably more so.
Posted by KarlEd (Member # 571) on :
quote:3. A rogue moon which moves in and out of the orbits of the gas giants and doesn't exactly follow the plane of the ecliptic, and which, by the way, is one of probably dozens like it.[emphasis mine]
Boy! there's stretching an arguement. Pluto crosses the orbit of Neptune, one of the "gas giants". It comes nowhere near to crossing the orbits of any of the others.
Posted by Jon Boy (Member # 4284) on :
It's still a valid argument, regardless of the number of other orbits that Pluto crosses. Those four groups of bodies have very little in common with each other; doesn't it seem a little odd to use one word to cover such dissimilar things?
Posted by BlackBlade (Member # 8376) on :
When my kid wants to know what the word "semantics" means, I will refer him to the astronomy classes he will have been, or soon will be attending.
edit: I personally am in the drop Pluto as a planet camp and use another planet as the basis for the planetary designation camp.
I really don't mind 5th grade astronomy being 1 planet easier than possibly 8 planets harder in the next 20 years.
Posted by theamazeeaz (Member # 6970) on :
quote:Originally posted by Hamson:
quote: Nobody in the IAU except Mike Brown wants the names Xena and Gabrielle.
Sounds like you're taking it a little personally there, theamazeeaz. Are you in the IAU?
I wish. I do get paid to do Astronomy, but I am still a student. I do know someone there in Prague, but she does work with galaxy structures and goes to completely separate presentations. The IAU meets every year to present papers and such. Oddly enough she didn't know that the IAU was looking at the planet issue, not being one of the "crazy planetary people".
The statment I made was based on the comments of one of my professors. He studies asteroids and has discovered some neat stuff about their properties. I asked him what he thought about the object and the name Brown had given it and he was rather mad. KBOs (Kuiper Belt Objects) and Asteroids are discovered often enough that the IAU has ground rules about how they are named. I don't know them off the top of my head, but one convention he mentioned was the that a less significant KBO would be unceremoniously assigned the name "Brown." As a minor planet person, Brown knows exactly how the IAU works, and what bothered my professor was that he did not respect the conventions and promoted himself and his planet names to the media. I'm also under the impression that my professor isn't the only person who feels this way. There's slightly more to it than that, but the conversation took place several months ago and I don't remember everyting that was said.
Posted by IanO (Member # 186) on :
quote:You DID suggest that the name Xena was after the TV show...
Well, more specifically, I mentioned the show after Xena and Gabrielle had already been mentioned as candidates Mike Brown wanted.
But I did like the show (for awhile, anyway.) Something self-consciously cheesy about it and Hercules in the mid 90s.
Posted by Sterling (Member # 8096) on :
I'm glad Pluto is still a planet. And I don't mind there being more planets in the solar system.
Anything that increases the amount of wonder in our universe is a good thing.
Posted by Jon Boy (Member # 4284) on :
What does the label "planet" have to do with the amount of wonder in the universe?
Posted by mr_porteiro_head (Member # 4644) on :
I'm glad that Pluto is a pluton. And I don't mind that there are more classifications of bodies in the solar system.
Anything that increases the amount of wonder in our univers is a good thing.
*warining: this post may not reflect the actual opinions of the poster
Posted by El JT de Spang (Member # 7742) on :
I say we get rid of all the names. Names are too freaking troublesome to remember.
What'm I, training for Jeopardy?
Let's do like I do with high school acquintances and coworkers in other departments; when I need to refer to them, I point in their general direction.
Posted by mr_porteiro_head (Member # 4644) on :
*points to sky*
Posted by FlyingCow (Member # 2150) on :
I could see dividing those four groups into different categories: solid planets, gas planets, and planetoids. A planetoid is different from an asteroid in that it has the "enough gravity to pull itself into a sphere" idea.
That would distinguish mercury from Jupiter well enough, and distinguish Pluto/Charon/Ceres from the other 8 planets (4 solid, 4 gas) well enough.
So, solid planets: Mercury, Venus, Earth, Mars; gas planets: Jupiter, Saturn, Uranus, Neptune; planetoids: Pluto, Charon, Ceres, Xena (or whatever its new name will be - I submit Pan, since it's small and troublesome).
Posted by Jon Boy (Member # 4284) on :
quote:Originally posted by mr_porteiro_head: I'm glad that Pluto is a pluton. And I don't mind that there are more classifications of bodies in the solar system.
Anything that increases the amount of wonder in our univers is a good thing.
*warining: this post may not reflect the actual opinions of the poster
I'm glad that polysemy is a shortcut to philosophical revelations.
Anything that increases the amount of wonder in our universe is a good thing.
Posted by KarlEd (Member # 571) on :
quote:Originally posted by Jon Boy: It's still a valid argument, regardless of the number of other orbits that Pluto crosses. Those four groups of bodies have very little in common with each other; doesn't it seem a little odd to use one word to cover such dissimilar things?
Does every word have to name an extreme specific? I mean, "mammal" covers an incredibly wider range of dissimilar things and no one squabbles about that. Why shouldn't planet be able to cover the range of things it would cover under the proposed definition. It's still a useful term. If you need further clarification, there are additional words you can use. "Pluton" is one of them, if you want to differentiate those from the general class of "planets". "Gas Giant" is another. I won't say that there are no legitimate gripes against the proposed definition, but the fact that it is broad enough to refer to more than one sub-class of object isn't one of them. (IMO)
Posted by Jon Boy (Member # 4284) on :
quote:Originally posted by KarlEd: Does every word have to name an extreme specific?
I didn't say that they do.
quote: I mean, "mammal" covers an incredibly wider range of dissimilar things and no one squabbles about that. Why shouldn't planet be able to cover the range of things it would cover under the proposed definition. It's still a useful term.
The question is, what traits are most important to determining whether or not something is a planet? Does this new definition include those traits while excluding other traits? I'm really not sure, to be honest; I'm still kind of waffling. But it does seem to me that it's better than the previous definition, which seemed much more arbitrary.
Posted by KarlEd (Member # 571) on :
quote:But it does seem to me that it's better than the previous definition, which seemed much more arbitrary.
That's because it was rather arbitrary. The issue is that there never really was a "previous definition", at least not in the scientific sense.
Posted by JLM (Member # 7800) on :
We need a planet Bob!
Posted by Gwen (Member # 9551) on :
quote:I could see dividing those four groups into different categories: solid planets, gas planets, and planetoids. A planetoid is different from an asteroid in that it has the "enough gravity to pull itself into a sphere" idea.
Cool--except: what is it that distinguishes "solid planets" from "planetoids"?
People: whales, humans, moles, bats, and platypuses (platypoda? Thanks Lost Boys) are all considered mammals, yet they have little enough in common with each other--they all have hair and they all have breastfeeding-capable females. Yet no one throws a fit because it's hard to memorize the names of all the mammals or because the classification is so arbitrary-seeming.
Posted by FlyingCow (Member # 2150) on :
The thing is, mammals are a division of a far larger classification system - first Animal, then Mammal, then further divisions. Planets don't have such a system.
I could see "Planet" being an umbrella term such as "spherical thing that orbits a star" - with further subdivisions beneath that. I'd say that Mercury through Mars have similar enough characteristics to warrant a subclassification. Jupiter through Neptune do too. Pluto, Charon and the other KBOs all share common characteristics which may or may not include Ceres in their subdivision.
If a scientific definition is to be made, there need to be further categories, I think.
I would support [ha ha, like my say matters one iota] a very broad definition of planet (such as an object having enough gravity to pull itself into a ball), with further categories such as "a ball composed of a hard crust and molten core", "a ball composed of mostly gas and liquid", "a ball composed of hard rock without a molten core", etc.
Would this be so out of line? It seems to follow more closely the Kingdom-Phylum-etc model of Biology.
Edit: Doesn't Star Trek have planetary subdivisions - e.g. a Class M Planet? Do planets have classes, or is that something ST made up whole cloth?
Posted by rivka (Member # 4859) on :
Star Trek technically made it up, but based on information from the Jet Propulsion Laboratories.
I did some research on the planetary classifications for a game I'm writing, and it seems that most people actually accept the Star Trek (Class L, Class M, etc...) listing above anything else, especially considering Star Trek's list is based on information provided by the JPL.
I spent hours looking for a JPL-hosted page with related information and couldn't find one that was satisfactory.
Besides, the Star Trek list is so much easier to work with, at least from a gaming standpoint. Situations where planets are in doubt don't come up, because the writer/game designer doesn't put themselves in to that situation.
In my game, every Class L is the same, every Class M is the same, etc...
Posted by FlyingCow (Member # 2150) on :
I like the wiki breakdown of rock planets, gas planets, and ice planets. Of course, within each, there could be further subdivisions for better accuracy of classification (for instance, a rock planet with liquid water v. one without).
Posted by Sterling (Member # 8096) on :
quote:Originally posted by Jon Boy: What does the label "planet" have to do with the amount of wonder in the universe?
Most people learn little more of astronomy than the names of planets in our solar system, the moon, and the sun. We don't learn a lot about asteroids, moons of Jupiter, comets, or other celestial bodies. We do learn planets.
Every chunk of rock we recognize oribiting the same sun as ours makes the universe seem a little closer, and our planet seem a little less alone.
That, to me, is wonder.
Posted by Orincoro (Member # 8854) on :
quote:Originally posted by KarlEd:
quote:3. A rogue moon which moves in and out of the orbits of the gas giants and doesn't exactly follow the plane of the ecliptic, and which, by the way, is one of probably dozens like it.[emphasis mine]
Boy! there's stretching an arguement. Pluto crosses the orbit of Neptune, one of the "gas giants". It comes nowhere near to crossing the orbits of any of the others.
No, I should be more clear: I'm thinking of how we we are going to categorize other planets in other solar systems, which are likely to have similar planets which don't follow the ecliptic and don't have tight eliptical orbits. Your right, its only neptune, but what about all the objects in the galaxy that do the same thing? There are probably millions.
Posted by Orincoro (Member # 8854) on :
quote:Originally posted by Jon Boy: What does the label "planet" have to do with the amount of wonder in the universe?
This is basic astronomy: Planets= wonder. What planet were you raised on, I wonder.
Posted by Gwen (Member # 9551) on :
He thought he'd been raised on a planet all along, but then it was discovered that it was tiny compared to the gas planets and so now he was raised on a large asteroid partly covered in water.
Posted by KarlEd (Member # 571) on :
Incidentally, does anyone know when the word "planet" began being used to include Earth? It's root means "wanderer" and was first used to describe objects which did not follow a sun/moon/stars like progression across the sky, but appeared to wander back and forth among the stars. At that time, Earth was probably largely considered the center of the universe and so it would have been absurd to consider Earth a "planet". I imagine even after a heliocentric model was widely accepted, it was still at least some time before Earth was routinely referred to as a "planet".
Any guesses?
Posted by Jon Boy (Member # 4284) on :
quote:Originally posted by Sterling:
quote:Originally posted by Jon Boy: What does the label "planet" have to do with the amount of wonder in the universe?
Most people learn little more of astronomy than the names of planets in our solar system, the moon, and the sun. We don't learn a lot about asteroids, moons of Jupiter, comets, or other celestial bodies. We do learn planets.
Every chunk of rock we recognize oribiting the same sun as ours makes the universe seem a little closer, and our planet seem a little less alone.
That, to me, is wonder.
So why not just redefine "planet" to include all the asteroids, comets, and Kuiper Belt objects in the solar system? Bam! Instant wonder.
Posted by Gwen (Member # 9551) on :
Or expand what most people learn about to include asteroids, comets, moons, and Kuiper Belt objects in our solar system. Or include more science fiction in school reading curricula. Insta-Wonder (tm)--New, expanded version, now with three more planets!
Posted by Gwen (Member # 9551) on :
Very relevant to the discussion at hand, plus really, really funny. Also read the comments.
Posted by Jon Boy (Member # 4284) on :
quote:Originally posted by Gwen: Or expand what most people learn about to include asteroids, comets, moons, and Kuiper Belt objects in our solar system.
That's just crazy talk.
Posted by Morbo (Member # 5309) on :
As well as my scenario above, where the COG or barycenter hovers at the boundary of a primary (I was thinking of a near circular orbit), there are two other scenarios (at minimum) that argue against the barycenter loci being part of the definition of planets, listed by CNN. The moon's orbit is increasing. Billions of years from now, the barycenter of the Earth-Moon system will be outside the Earth, and the Moon will not be a moon.
And CNN's second possibility: a system with a highly elliptical orbit could have the barycenter in the primary part of the orbital period, and outside of it in other parts of the orbit, causing the secondary object to be variously defined as a moon and a planet in every orbit!
No, it's just not central to the definition of moons and planets, and leads to more problems than it fixes.
quote: It gets stranger.
Astronomers expect to find hundreds of Pluto-sized objects in the outer solar system. If one has a satellite that is round, and which has a certain eccentric orbit -- meaning the two objects come very close together at one point and then diverge greatly -- then the barycenter could dip inside the larger object during part of the orbit, Laughlin explained.
In such a case, the smaller object would be defined as a moon part of the time and a planet the rest.
A vote on the new definition is scheduled for August 24 at the IAU meeting in Prague.
quote:Originally posted by Gwen: Or expand what most people learn about to include asteroids, comets, moons, and Kuiper Belt objects in our solar system. Or include more science fiction in school reading curricula. Insta-Wonder (tm)--New, expanded version, now with three more planets!
Yeah, but we can stick with discovering ACTUAL planets to increase our wonder. Astronomers now know of or suspect the existance of hundreds of extrasolar planets near our own solar system. That is plenty of wonder to me.
Posted by Gwen (Member # 9551) on :
Yes, but again, what counts as an ACTUAL planet? As the person in the link I posted points out, the four gas planets are totally different from Mercury, Mars, Venus, and Earth, but we insist on putting them in the same category (regardless of size differences! and atmospheric differences! and the actual makeup of each planet! and the existence or non of rings!) as "planets" when it would make just as much or more sense to follow his plan:
quote:We all know that the only real planets — the big ones that accreted from the solar disk right at the beginning — are Jupiter, Saturn, Nepture and Uranus. They're self-accreting bodies that aren't massive enough to undergo fusion and that formed in orbit around a star. OK? That's a planet.
Naturally you're biased: you live on Earth after all. But I have to tell you, these days we have this theory called the heliocentric model that holds that Earth isn't the centre of the universe. Guess what? Earth isn't a real planet, either. It's just a ball of rocky left-overs that didn't get its fair share of gas when the accretion disk was still swirling. Indeed, the same goes for Mars, Venus, and Mercury. These tiny rocks (Earth, the largest, is barely a thousandth the mass of Jupiter) orbit in the wrong darn place, far to close to their primary star to have any hope of hanging onto a volatile envelope of hydrogen and a bit of helium. In fact, I think it's about time the IAU bit the bullet and admitted that these dwarfish rocky cores are just that, and introduced a new category, "failed planetary nuclei", to define the rocky Earthlike bodies of the inner solar system.
Given that the "Plutonoids" are believed to be mostly condensed gassy stuff, we can (subject to confirmation) then redesignate them as "failed planetary atmosphere fodder". The asteroids and small KBOs can then be allocated to one group or the other, or a fourth, catchment category: "irritating little [deleted]". And the rationalization of the solar system is done.
It'll be so much easier to teach kids the names of the planets when we've pruned them back to four!
Why not? If we're going to demote Pluto, and not recognize Charon as a planet, then why not go all the way with a much more logical model?
And as far as the moon/planet thing goes: yes, it'll be inconvenient to define moon in such a way that it's possible for certain bodies to be planets through some of their orbits and moons through the rest, but that's just the way the cookie gets stomped on and completely obliterated. Charon, at least, is a clear-cut case in the moon/planet controversy, because it consistently orbits around a point outside of Pluto's planetary sphere.
Actually, the coolness of having half (or a third or a fourth or two-fifths) of a planet is sure to increase children's senses of wonder about the universe. It's like the elementary-school trick of "how many fingers am I holding up" when one of the fingers is a thumb (and therefore apparently not a finger or something). You'll be sure to have every school-attending person in America (at least) knowing that piece of trivia.
Posted by theamazeeaz (Member # 6970) on :
quote:Originally posted by Gwen: Yes, but again, what counts as an ACTUAL planet? As the person in the link I posted points out, the four gas planets are totally different from Mercury, Mars, Venus, and Earth, but we insist on putting them in the same category (regardless of size differences! and atmospheric differences! and the actual makeup of each planet! and the existence or non of rings!) as "planets" when it would make just as much or more sense to follow his plan:
quote:We all know that the only real planets — the big ones that accreted from the solar disk right at the beginning — are Jupiter, Saturn, Nepture and Uranus. They're self-accreting bodies that aren't massive enough to undergo fusion and that formed in orbit around a star. OK? That's a planet.
Naturally you're biased: you live on Earth after all. But I have to tell you, these days we have this theory called the heliocentric model that holds that Earth isn't the centre of the universe. Guess what? Earth isn't a real planet, either. It's just a ball of rocky left-overs that didn't get its fair share of gas when the accretion disk was still swirling. Indeed, the same goes for Mars, Venus, and Mercury. These tiny rocks (Earth, the largest, is barely a thousandth the mass of Jupiter) orbit in the wrong darn place, far to close to their primary star to have any hope of hanging onto a volatile envelope of hydrogen and a bit of helium. In fact, I think it's about time the IAU bit the bullet and admitted that these dwarfish rocky cores are just that, and introduced a new category, "failed planetary nuclei", to define the rocky Earthlike bodies of the inner solar system.
Given that the "Plutonoids" are believed to be mostly condensed gassy stuff, we can (subject to confirmation) then redesignate them as "failed planetary atmosphere fodder". The asteroids and small KBOs can then be allocated to one group or the other, or a fourth, catchment category: "irritating little [deleted]". And the rationalization of the solar system is done.
It'll be so much easier to teach kids the names of the planets when we've pruned them back to four!
Why not? If we're going to demote Pluto, and not recognize Charon as a planet, then why not go all the way with a much more logical model?
And as far as the moon/planet thing goes: yes, it'll be inconvenient to define moon in such a way that it's possible for certain bodies to be planets through some of their orbits and moons through the rest, but that's just the way the cookie gets stomped on and completely obliterated. Charon, at least, is a clear-cut case in the moon/planet controversy, because it consistently orbits around a point outside of Pluto's planetary sphere.
Actually, the coolness of having half (or a third or a fourth or two-fifths) of a planet is sure to increase children's senses of wonder about the universe. It's like the elementary-school trick of "how many fingers am I holding up" when one of the fingers is a thumb (and therefore apparently not a finger or something). You'll be sure to have every school-attending person in America (at least) knowing that piece of trivia.
The idea of a planet first came about because people wanted to name the five objects that moved with respect to the background stars: Mercury, Venus, Mars, Jupiter and Saturn. It was quite awhile before humans figured out that those "stars" were all moving around the sun- as were we.
Telescopes brought us the ability to see fainter objects and we (okay Galileo) discovered moons around planets besides our own, asteroids and yet more planets. Not to mention a whole host of fainter stars, galaxies and nebulae.
Of course the gas giants are different from the other planets. That's why we call the gas giants Jovian planets and the other ones terrestrial planets. Plutons is a new catergory for icy space junk. That's how we differentiate the size.
The category planet means the object Orbits A Star and fusion didn't happen. So the gas giants are planets because they failed as stars (so they are NOT stars) and orbit our sun. The terrestrial planets are planets because they orbit our sun. The IAU wants to define plutons as planets because they are a cut above space junk, being round. Mars's moons and most Asteroids (clearly not Ceres) are too small for their gravity to make them round. Planet= BIG thing that goes around the sun. Everything smaller- Asteroids, etc. are space junk that happens to orbit the sun by itself. We've got at least 43000 named Asteroids and we've got to draw the line somewhere.
Moons are defined by the fact that they orbit planets which orbit the sun. It's not a size thing as many of the larger moons of the gas giants are bigger than the smallest planet (the cool chart I have that shows which ones are bigger or smaller is only accessible at school http://www.spacetoday.org/SolSys/Moons/MoonsSolSys.html has the best info I can find. Ganymeade, one of Jupiter's moons is bigger than both Mercury and Pluto). I have never heard of any body naturally orbiting a moon. There is a moon Dactyl which orbits the asteroid Ida.
Posted by Nighthawk (Member # 4176) on :
CNN posted a story yesterday in which the only thing they said is that the Moon will eventually become a planet. And "eventually" means in several billion years, enough time for the moon to recede and the center of rotation to be outside of Earth's mass.
Posted by Gwen (Member # 9551) on :
Theamazeaz: I agree with all that. My point was, if the reason why Pluto shouldn't be a planet is because it's different from Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune in a few points (different shape of orbit, really small, and partly made of ice), and the reason why Ceres and 2003 UB313 shouldn't be planets is because they're small and it'll be too hard to memorize all the planets, any of those reasons could be used to draw the line at only Jovian planets being considered planets: Mercury, Venus, Mars, and Earth are really small, comparatively speaking, and have a rather different makeup, and it'll be easier to memorize planets when there's only four of them. Yet no one's (seriously) calling for the removal of Earth from the planetary category, mainly because we live on it. And the point about size is that size shouldn't (in my opinion) be a defining point in the controversy; just because Pluto is smaller than Luna doesn't mean it's not a valid planet, any more than Ganymede being larger than Mercury (interesting information!) makes Mercury less of a planet. In fact, I would go so far as to say that if anything in the asteroid belt is large enough to be spherical, it's a planet. (Although not necessarily one that'll last very long.) So my definition of planet would be something like Planet=ROUND thing that goes around a star.
And won't the definition we come up with for our solar system apply to others, too? If we define planet as "something that goes around the primary that is larger than Luna and has an orbit like the other planets" (ignoring the obvious circularity of trying to figure out which of the space junk going around the primary counts as a planet in order to define the other planets), we might end up excluding a planet with an orbit more like the first nine planets of our solar system just because more of the planets have a Pluto-like orbit. Hmm...
Posted by MyrddinFyre (Member # 2576) on :
Not sure if anyone linked this yet, but I read this article today. I spose it has a little more detail than previous statements. Anyway, I would be very sad if Pluto were demoted. It's always been that little planet just barely hanging on to our MVEMJSUNP System. I can't imagine us saying, Now, now, Pluto, run along and play with the asteroids, you're not wanted here.
Haha, I think it's time I went to bed... I'm getting emotional over Pluto's planethood!
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