It's smaller than Pluto and MUCH further out. NASA will have a news conference about Sedna on Monday.

Sedna (http://www.theaustralian.news.com.au/common/story_page/0,5744,8968352%255E29098,00.html)

Vaccum Pony

Interesting. So I guess we'll have to decide exactly what a "planet" is ... what qualifies and what doesn't, eh?

And how many of them do Jupiter and Saturn have round them?

Even in the article they call it a "planetessimal" so I really don't think it will become a planet.

People originally refered to Chiron as a "mini-planet," and made much of the discovery of Quaoar (1992, wasn't it?) as the first Solar System body beyond Pluto. Still, the more of these icy planetisimals turn up, the less remarkable they seem. Confering " major planet" status on anything 2000 km or more in diameter - and not orbiting a larger planet - would surely devalue the classification.

I once read a definition of "planetary body" as any mass too small to form a star - from bodies dozens of times heavier than Jupiter down to individual subatomic particles (by Isaac Azimov, in "The Collapsing Universe").

So is this the 10th planet or another body we will ignore? Is this the famed panet X?

No, no, and No.

Another link about this:

http://www.spitzer.caltech.edu/Media/releases/ssc2004-05/index.shtml

So is this the 10th planet or another body we will ignore? Is this the famed panet X?

Unfortunately Sedna is the third planet O. Thus, the tyrannical lizards from Deneb have won the game of Tic Tac Toe for control of our solar system. Humans have searched for planet X for many decades, but were unable to locate such a planet within the 70 years allotted for their turn. Secretary-General Kofi Annan of the United Nations, speaking for the Human team expressed disappointment at their loss, but congratulated The Denebians on a game well played.

As per Galactic custom, the Denebians will now eat the Humans.

Sedna has such a wide orbit its only anywhere around here ever 10,000 years :)
____________
(_o__________) lol i tried to show an example of its orbit, the "o" is our solar system. and the ____ are elliptical =)

it's a comet orbit lol

My friend told me about this and got my hopes up, did they finaly find Nibiru, Noooo I bet its just an asteroid agian, but any way welcome to our solar system sedna - even though youv probibly been sitting up there for 5 billion years

SORRY! I was 10 years wrong in saying that Quaoar turned up in 1992! However, I'm certain that SOME Kuiper belt object was first discovered that year.

Even if Sedna is not to be classed as a 10th major planet, its discovery indicates there may be many other large bodies orbiting the Sun at such vast distances - maybe some bigger than Pluto, or even Mercury.

Or maybe even a Jupiter-sized planet located almost 100 AU away from our sun :)

That would be an interesting find indeed ...

That would be an interesting find indeed ...


Well the search is on already!
The direction of the galactic centre is the place to look. and probably at a distance of about 400 AU. If i remember correctly the early solar system had perhaps a hundred planets, most of those would have been involved in collisions or been flung out to reside in the Oort cloud.
So i imagine that an earth sized planet may exist out there...

The alternative is rather boring, and just involves a passing star to jolt the newly found Sedna into it`s present-day comet orbit...

Object 2003 VB12 :

q: perihelion distance (AU): 75.796
Q: aphelion distance (AU) : 988
H: absolute visual magnitude; 1.7
i: inclination of orbit : 11.9
e: eccentricity of orbit : 0.857

Just a little image of Sedna made with Celestia software (http://www.forteantimes.com/forum/attachment.php?postid=356107)...

blobrana....
well, ahem, we'll never know till we find them.....

and eburacum,
thanks for the image. I wonder if there's any frozen gas which may be dark-colored in nature? Because if the answer is no, wow...

29 Kelvin? My God... just think how cheap Sedna-ite popsicles are!