PLuto vs. Sedna

[parintachin5`]

I went to find out what constitutes "planet" and this is the ebst that turned up: http://www.gps.caltech.edu/~mbrown/sedna (http://www.gps.caltech.edu/~mbrown/sedna) (scroll down to "what is the definition of a planet")

It makes a good point, namely that we don't have any solid definition of what makes an object a planet and the one thing that fits both scientific evidence and precedent is an object that is the only one of its comparable size in it's vicinity. For example, each asteroid (Ceres, etc) is considered an asteroid, not planet, because there are others of a comparable size in it's vicinity.

It then brings up Pluto. There's been debate about Pluto for years, talk of "demoting" it's status as planet because it's no different from other Kuiper Belt objects. The article makes a good point and as someone with a strong scientific background (not in physics, obviously) I'm not going to dismiss science for what's become an astrological staple. But Pluto's worked relaly well in astorlogy, so the question is then, "why?"

Maybe there's enough common ground between Sedna's and Pluto's mythology that we've caught on to the accurate things and have been dismissing the non-accurate? Should Pluto, having no reason to be considered a planet besides an initial mistake, remain a part of astrology? How should Sedna be incorporated?

Your thoughts?

[KEishin]

Well, a point can be made about Pluto not being a planet if you look at purely physical characteristics.

My view is that a planet is:

a planet orbits the Sun (rather than a moon that orbits a planet) and
It must be big enough that its own gravity pulls it together into a sphere - i.e. it must be round.
Many objects in the solar system that are generally larger than about 400 km across tend to be more or less spherical (rather than irregular or 'potato-shaped'). Pluto, although smaller than several moons, qualifies under this definition. About a handful of asteroids also qualify. I would call all of these minor planets.

As far as the other Trans-Neptunian objects being discovered? These new Kuiper Disk objects are about 10 times smaller than Pluto, less than the nominal 400km to be round, so that they certainly do not qualify as planets. Therefore, I am sticking with Pluto as a planet; but just because Pluto is small (about the size of the USA) that does not mean we should 'demote' it.

And as an astrologer, my final determination is this: what does Pluto do to charts as it goes through the signs and makes its different aspects? The answer is 'something pretty signifigant'. The research I've read (albeit not everything out there) shows that Sedna does not travel in tandem with Pluto. So if it's not Pluto causing those astrological events, what is it? This is all just IMHO.

[Fluffmeister]

Well, there will be an "official" answer soon: the International Astronomical Union (IAU) are the body who are responsible for naming planets, and deciding what is and isn't a planet.

Now, Keishin's point about ingresses through signs is very well made - and not one that the IAU will pay any attention to because they don't like us astrologers very much! As Keishin says, Sedna isn't in tandem with Pluto - it has such a weird orbit it spends centuries in some signs. It's pretty close to us at the moment, so it's "whizzing" through signs (spending just decades in some!)

The new planet (currently called 2003UB313) does have some very interesting patterns as it moves into each sign, and I do think this new one really does have astrological significance (IMHO) - its ingress into Taurus corresponded with the Renaissance, for instance. And indeed, the IAU may just decide that it really *is* a planet after all:

http://www.iau.org/IAU/FAQ/2003_UB313.html

[parintachin5`]

Thanks for your replies. It's a good point about passing through the signs. More to think about, as always... :)

[Kadynas]

So if it's not Pluto causing those astrological events, what is it? This is all just IMHO.
While I definitely think Pluto's importance has proven itself worthy of the astrological pantheon, there still is some question as to more planets in the area to be discovered. :) Thos who know me know I'm a big fan of Valerie Vaughn's Transpluto theory, ie: Persephone. Pretty much the idea is that the gravitational pull of Pluto alone is not enough to account for the weird orbits... so something else must be in the vicinity and Sedna wasn't found in the place they thought Transpluto would be, so it's a definite possibility that it's still out there.

I'm also very put out at the naming of Sedna... I know it's all well and good to break tradition every once and a while: I am mostly Fire after all. :lol: But having Sedna outside the greco-roman pantheon of the other planets makes it a bit difficult if you try to relate it to aspects between them. With the others, you could always draw on the mythology when you got stuck... with Sedna, it's like blending two different worlds... Haven't paid any attention to it yet... However if I were, I'd probably decide which deity of the greco-roman set she most closely resembles and go from there... :)

[KEishin]

Yeah that kinda bothered me too, even though I am a pan-pantheonist:lol:

But who could it be for female in Greco-Roman? Persephone/Prosperina? Definitely not Hekate or one of the Fates or Furies. And Alcyone's already in the Pleiades . . .

That about exhausts my knowledge of appropriate females in Greek myth this early in the am.

[Fluffmeister]

And I don't think we can count Sedna as a planet - if we do, we're pretty soon going to have hundreds of planets, and there just aren't enough Graeco-Roman dieties to go round! And with Sedna's 10,000 year orbit it's going to be very difficult to see what effect she has.

This new body, though, if it *is* a planet will have to have a Graeco-Roman name (because thus spake the IAU).

[parintachin5`]

I think the point of the article though, Fluffmeister and keishin, was that Sedna should count as a planet precisely because there aren't other objects of comparable size around her (it). She is considered as part of the Kuiper belt, but stands alone.

Of course, this begs the question: 1)her orbit is so elliptical, what if now she stands on her own and in 800 years she doesn't?

So I'm still up in the air, I can see both sides on this one (or maybe that's just a Libran Mercury speaking :P)

[KEishin]

Well Pluto has a very elliptical orbit (off the ecliptic). Is that part of the reasoning behind the whole 'let's demote Pluto' bit?

[parintachin5`]

Again, drawing form the article and me not being an astronomer/physicisist in any way: No. They want to "demote" Pluto because when it was discovere, they thought it was the only object the sun that there was in that region. Then they discovered a whole bunch of others. And so why should they keep Pluto separate- what does Pluto have to differentiate it form everything else in its region?

I only know what a few articles along the way have written... So that's as much as I can answer on the topic. I really don't know any more.

[KEishin]

Gotcha!
I'm no astronomer either, but I enjoy parts of it as a hobby. So we're in the same boat!

[Fluffmeister]

And so why should they keep Pluto separate- what does Pluto have to differentiate it form everything else in its region?


Pluto has several things that differentiate it: it's not a gas giant, it has an elliptical orbit, and it's inclined to the ecliptic. These are characteristics of Kuiper Belt Objects like Chiron rather than the sort of planets that astronomers expected to find (namely, more gas giants).

If Pluto had been discovered now instead of 75 years ago, it would almost certainly have been classified as a Centaur (like Chiron), and not a planet. The question is not what differentiates it from other bodies in the region, but why is Pluto considered more significant than Chiron?

Sedna is currently unique in being the only body that lies way beyond the Kuiper Belt, and is probably an Oort Belt Object - the first to be discovered. However, it's unlikely to remain unique for long!

[Agaliha]

I just found out about Sedna tonight :bigredblu I feel slow! :twitch:
I came across this article: http://news.bbc.co.uk/1/hi/sci/tech/3511678.stm

And this site: http://www.gps.caltech.edu/~mbrown/sedna/ and http://www.gps.caltech.edu/~mbrown/sedna/#planets

Pretty intersting :toofless:

Um, I am confused though...I know Pluto is called a planet, but I thought they now thought it wasn't because it's orbit is totally different from the rest of the solar system...and something about it being a foreign object stucked into our gravity pull :huh:

[Fluffmeister]

Um, I am confused though...I know Pluto is called a planet, but I thought they now thought it wasn't because it's orbit is totally different from the rest of the solar system...and something about it being a foreign object stucked into our gravity pull :huh:

Well, everyone's confused! That's what this thread has been about :crown:

And we *still* haven't heard from the IAU to see if they are demoting Pluto or not.