Sedna; the "10th" Planet?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jzdnzr</i>
<br />Does anyone have "ANY" word regarding [Sedna]? So far NO-one has answered my question, regarding its existence or anything.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You can find a ton of information on the internet with any search engine. For example, www.gps.caltech.edu/~mbrown/sedna/ Sedna is a relatively large member of the new asteroid belt beyond Neptune (not associated in any way with the Oort cloud of comets). But there are now over 700 members of that belt, and Sedna is definitely not large enough to be called a planet by any existing definition. So nobody's very excited about it in that sense. -|Tom|-

Just read the reports, and had to comment.
I'm sure this is old news to some.

I suggest that Sedna is a surviving escaped moon of the hypothetical Planet X, thus proving its existence as well. I base this on:

1.) Highly elliptical and inclined orbit.
2.) Perihelion just inside of where Planet X should be.
3.) Mass is far too low for a major planet.
4.) No other cause appears to exist for its slow rotation.
5.) Orbit is too elliptical to have fissioned from the Sun as is.
6.) Low probability of a successful orbit modified by collision.


Further, I suggest that Planet X has since exploded, based on:

1.) Strongly suspected presence of an asteroid belt.
2.) Minor dirt clod suggested by Sedna's observed brightness cycle.
3.) Neptune perturbations don't quite jive for a singleton culprit.
4.) If Sedna is visible, then so is a major planet at that distance.
5.) No asteroidal moons as expected if Sedna was in orbit at event.


Finally, I suggest that Planet X exploded in the relatively recent astronomical past, based on conjecture that a well spread out asteroid belt would have been recognized as such by its perturbations.

Credits where they are due; some of those points came from Dr. Tom van Flandern's book, "Dark Matter, Missing Planets, and New Comets".


--


I also saw a discussion on the proper definition of a planet. I think the Meta Model intuitively provides the cleanest one yet:

A planet is a body that fissioned from a star.

Further:
A moon is a body that fissioned from a planet.
An asteroid is a chunk of a destroyed planet or moon.

Reaching a bit here:
A comet is a body with a gaseous atmosphere that periodically approaches a source of radiation sufficient to produce a coma.