# 10th planet found



## Brian G Turner (Jul 30, 2005)

Claims of a 10th planet are finally being made - though by all accounts, not only is it very distance, it seems to be little bigger than Pluto.

So, are we're looking at a string of Kuiper bodies being discovered for the future, and all classed as planets?

http://news.bbc.co.uk/1/hi/sci/tech/4730061.stm



> Astronomers in the United States have announced the discovery of the 10th planet to orbit our Sun.   The largest object found in our Solar System since Neptune was discovered in 1846, it was first seen in 2003 but has only now been confirmed as a planet.
> 
> Designated 2003 UB313, it is about 3,000km across, a world of rock and ice and somewhat larger than Pluto.
> 
> ...


----------



## Alexa (Jul 30, 2005)

The big question is: "What a planet is by definition" ? More: "What is the definition of a planet ?"

How can be the new object considered a planet if astronemers cannot define a planet ?


----------



## Eradius Lore (Jul 30, 2005)

i thought they found the '10th planet' over a year ago, yeah because i remember asking one of my collage teachers about it, bah old news!


----------



## Brian G Turner (Jul 30, 2005)

Yep - apparently they first spotted this in 2003 - but they couldn't confirm the details of its orbit, etc.


----------



## Alexa (Nov 12, 2005)

The 10th planet has a nickname, Xena. Its moon is of course Gabriel for those who knows the adventures of Xena, the Warrior Princess. The International Astronomical Union has to approve these names, in order to be official.

http://www.utcecho.com/media/paper483/news/2005/10/20/Culture/Xena-Found.Among.The.Stars-1028310.shtml?norewrite&sourcedomain=www.utcecho.com


----------



## markmid (Feb 17, 2006)

Have there been any noticeable updates on this story?


----------



## Tritonian (Mar 4, 2006)

i don think it is a planet, i mean there is alot of kuiper belt objecto out there, i think they should be a planet size limitaiton on it or something...


----------



## Hibye23 (Mar 5, 2006)

There is planet classification, it needs to be 800 miles wide or bigger to be a planet at least i think. And there a 13 planet and pluto has 3 moons.


----------



## speedingslug (May 27, 2006)

Xena is 100 km bigger in diameter than Pluto.
Has an eleptical orbit of 557 years, at some stage comes closer to the sun than Neptune.
Gabrielle has an orbit of 14 days

In fact Pluto amay be downgraded from being a planet at all yet !


----------



## kyektulu (May 28, 2006)

*That is fascinating, I wonder how many more undiscovered planets there are in our solar system...
Keep us updated please Brian. 
*


----------



## cornelius (May 28, 2006)

speedingslug said:
			
		

> In fact Pluto amay be downgraded from being a planet at all yet !


 
yes, we had a discussion it in class, seems that Pluto has two qualities short of being a real planet


----------



## Maxwell Jennison (Jun 5, 2006)

Well, technically, there is no such thing as a "planet" as it's never really been defined. But that's soon to change, as the International Astronomers Union will be putting the definition to a vote in August. They hope to announce their decision by early September.

The last time this need to define it came up, they didn't really come to a deciding factor, but they did limit it down to three choices:

1. A planet is any object in orbit round the Sun with a diameter greater than 2000km. Thus, we'd now have ten confirmed planets...the nine we all know, and "Xena." This was the favorite of the three amongst the IAU, and could very well become the norm. This was also the laziest choice, as the size was based on Pluto, having nothing to do with science. It was a cultural decision, as we all learned in school that there are nine planets, and they really didn't want that to change at the time. Now, with Xena, they have no choice but to rethink it.

2. A planet is any object in orbit round the Sun that is dominant in its immediate neighborhood. Thus, Pluto is not a planet, nor would any of the Kuiper Belt objects be. This was the least favorite of the three, but it was not without it's supporters. There are quite a few scientists who don't think Pluto should be considered a planet.

3. A planet is any object in orbit round the Sun whose shape is stable due to its own gravity. If this becomes the accepted norm, Xena won't be the _tenth_ planet as 1 Ceres and 4 Tellus (two asteroids) would now classify as planets, and we'd all have a lot of catching up to do to learn all the dozen+ planets in the Solar System. Note that while moon may go around the sun, they orbit other bodies, so Luna (The Moon) would still not be classified as a planet (sorry to clarify, but my parents questioned me on that when I told them all of this...I'm the only one in my family that has any grasp on astronomy).

The part that confuses me is all three definitions state that a planet has to be something that orbits round the Sun, which is our star, not just a generic word for a star. I think they're gonna have a little more work ahead of them, especially since 150+ "planets" have been discovered in other systems. Any way they take it, all the science books will undoubtably have to be re-written, as for the first time in astronomy, we'll have finaly defined the word planet. About time, too.

This geeky rambling brought to you by Max: Stellar Nerd Extraordinaire.


----------



## j d worthington (Jun 5, 2006)

Actually, thanks for the information; I'm sure quite a few people here will be more than a little interested.


----------

