Pluto

[umpa_lumpa]

Do you think that Pluto is a planet?

 

[newtonian]

umpa_lumpa - In common English usage - Yes.<br /><br />However, it does depend on what definition of planet you are using.<br /><br />For example, size alone won't work in view of large moons.<br /><br />Having individual orbits won't work since large asteroids have individual orbits.<br /><br />However, large + individual orbit does seem to be the consensus - and that would mean there are likely other planets out in the Oort cloud, etc.

 

[umpa_lumpa]

Do you think that pluto could just be a big rock from the <br />Kuiper Belt? It's revultion is so abnormal i couldn't have formed with the rest of the solar system could it?<br /> <br />Thank you for your replies.

 

[vogon13]

Pluto appears to be in a 2:3 resonance (like several other KBOs) with Neptune. Parameters of the 'original formation orbit' will remain forever unknown.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[tplank]

Would calling it a "planetoid" make everybody happy? I also like the term "plutoid"...it has a nice sound and cushions the demotion by making Pluto the head of its class. <div class="Discussion_UserSignature"> <p>The Disenfranchised Curmudgeon</p><p>http://tonyplank.blogspot.com/ </p> </div>

 

[newtonian]

umpa_lumpa - If I remember correctly Pluto was smaller than Mickey, Goofie and even Minnie!<br /><br />Could Pluto be said to be a dog star?<br /><br />I'm not being Sirius, btw.

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Kuiper Belt? It's revultion is so abnormal i couldn't have formed with the rest of the solar system could it? <p><hr /></p></p></blockquote><br /><br />There are many Kuiper Belt Objects (KBOs for short), and probably a lot more than have been discovered. Not all are in terribly eccentric or inclined orbits; the overall distribution will become better known as more KBOs are discovered. But yes, there seems to be a trend towards more highly inclined orbits the farther out one goes. I don't see any reason why KBOs couldn't have formed with the rest of the solar system, though. Either in their current orbits or in some other orbit; there are a number of theories that they may have been perturbed from their original orbits by interactions with large passing extrasolar bodies, undiscovered large planets, or even one another. Some of those theories are more plausible than others, IMHO, but in general the basic principle is plausible. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[dark_energy]

I find Pluto to be a planet because it is quite large to be an asteroid, and it has its own satellite. <div class="Discussion_UserSignature"> </div>

 

[rfoshaug]

<blockquote><font class="small">In reply to:</font><hr /><p><br />If I remember correctly Pluto was smaller than Mickey, Goofie and even Minnie!<br /><br />Could Pluto be said to be a dog star?<br /><br />I'm not being Sirius, btw.<br /><p><hr /></p></p></blockquote><br /><br /><img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[umpa_lumpa]

Thankyou everybody.

 

[bdewoody]

So, is Pluto going to be reduced in status to a "minor" planet or a large asteroid.<br /><br />And what will the definition of "planet" be? A spherical object of at least XX mass that is in orbit around a star (as opposed to in orbit around a planet).<br /><br />Inquiring minds want to know. <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[harmonicaman]

We've gone around and around on this topic in here and there is no general consensus of opinion. The answers you seek are in the hands of the The International Astronomical Union (IAU), which is the <i>"Internationally recognized authority for assigning designations to celestial bodies and any surface features on them"</i>.<br /><br />In particular, the IAU Working Group for Planetary System Nomenclature (WGPSN) is the seminal authority on this matter (I believe) and is assigned with the unenviable task of disambiguating the Solar System.<br /><br />We are probably decades away from learning the definitive fate of Planet Pluto and formulating a firm definition of what a planet is. We have so much more to learn about what is out there; any decisions made now would likely be premature and require revision in the not too distant future; and there really is no rush...<br /><br />One thing is for certain though; changes will occur as our knowledge grows -- and that's what science is all about!

 

[MeteorWayne]

At our local astronomy club, we debate this issue a lot, for fun and education. <br />I take the viewpoint that Pluto is not a "planet", but rather one of the TNO's (Trans-Neptunian-Objects).<br />What's most interesting is the reaction of the two people that I have this debate with the most.<br />One guy we have a lot of fun with it, realizing there are good points on both sides. Quite enjoyable and educational for the audience.<br />The other goes berserk, saying he knows what is right and gets really irritated. Very closed minded.<br />This is a question with a lot of interesting arguments to be made, and as h-man said the "official" decision will be made by the IAU in the future.<br />I expect to win the argument as more and larger TNO's are discovered, but I could be wrong <img src="/images/icons/smile.gif" />. That's the challenge and beauty of science, we learn more and more ever day.<br />A planet by any name would smell as sweet.....<br /><br />Meteor Wayne <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[vogon13]

Stable orbit about the sun, 3 satellites, atmosphere with climate,<br /><br />IT AIN'T A FARKIN' ASTEROID ! ! ! ! ! ! ! ! !<br /><br /><br /><br /><br /><br /><br /><br /><img src="/images/icons/smile.gif" /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[romulan_invader]

The People at a NASA call it a dwarf.

 

[MeteorWayne]

Good points!<br />However that may apply to many TNO's as well.<br />Want to come to the observatory for a debate <img src="/images/icons/smile.gif" />? <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[mikeemmert]

Well, there's several kinds of TNO's. There are cubewanos, plutinos, twotino's, and scattered disc objects. There are cubewanos with inclinations near the plane of the ecliptic, and cubewanos with seriously inclined orbits. There are TNO's with different colors. And then there are planemos and Oort cloud objects. There might be Lagrangians.<br /><br />Statement of fact: I'm biased towards classifying these objects dynamically. And that's not fair or anything like that, I just like working with orbital dynamics. Some might have a meteorological bias, which would have the most bearing on whether or not an object could, at least in principle, support a biosphere, so that's as legitimate as a dynamical bias. There's mass bias, too. And when we start seeing more objects orbiting other stars, some presently unimaginable bias might prove useful.<br /><br />Best bet is for the IAU to Define and Rule. And if the situation changes due to new discoveries, as it has twice already, then they have to change the rules. <br /><br />I think those who want Pluto to be a planet are unwilling to learn all those names and what they mean. That's limiting. My opinion is that they should stop calling it a planet. It doesn't fit in with the other 8.<br />

 

[romulan_invader]

Ît is a dwarf planet.

 

[MeteorWayne]

That's not a bad definition IMHO. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[romulan_invader]

Yes I like the word because the Pluto is a Planet but is to big to be Moon. BUt some moons we have in this system are bigger than a "planet." SO is a confusing idea. So a little planet is a "Planet." So NASA says it is a dwarf planet. It is a good name. It can fit very well. I think so.

 

[MeteorWayne]

No one has said it is officially a dwarf planet. NASA has no authority to do that.<br />It's just a darned good idea.<br />Of course, TNO fits too <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[romulan_invader]

TNO nobody understand that. People understand "planet" as a name. TNO has a no meaning for most people on the earth.

 

[MeteorWayne]

That should change, IMHO <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[3488]

Pluto & 2003 UB313 are the largest currently known members of the Kuiper Belt. Either Pluto is demoted to KBO status or 2003 UB313 (Xena) is granted full planetary status.<br /><br />There are seven moons in our solar system larger than Pluto (largest first in descending size order).<br /><br />Ganymede (Jupiter).<br />Titan (Saturn).<br />Callisto (Jupiter).<br />Io (Jupiter).<br />Moon (Earth).<br />Europa (Jupiter).<br />Triton (Neptune).<br /><br />The KBO 2003 UB313 (Xena) is slightly larger than Pluto & the Saturn moons, Rhea & Iapetus & the Uranus moons Titania & Oberon are not that very much smaller than Pluto.<br /><br />IMO Pluto is set to lose planetary status eventually. <br /><br />Small planets, large moons & large KBOs in the solar system (largest first in descending size order).<br /><br />Earth (Planet).<br />Venus (Planet).<br />Mars (Planet).<br />Ganymede (Jupiter moon).<br />Titan (Saturn moon).<br />Mercury (Planet).<br />Callisto (Jupiter moon).<br />Io (Jupiter moon).<br />Moon (Earth moon).<br />Europa (Jupiter moon).<br />Triton (Neptune moon).<br />2003 UB313 / Xena (KBO)*<br />PLUTO (KBO)**<br />Titania (Uranus moon).<br />Rhea (Saturn moon).<br />Oberon (Uranus moon).<br />Iapetus (Saturn moon).<br />2004 DW / Orcus (KBO)***<br /><br />* Largest known KBO.<br />** Second largest known KBO.<br />*** Third largest known KBO. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[MeteorWayne]

3488,<br />Great list, thanx for the effort you put in!<br />MW <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>