The tenth planet-Sedna

[Y2A]

Story from BBC NEWS:
http://news.bbc.co.uk/2/hi/science/nature/3511678.stm

Astronomers discover 'new planet'
By Dr David Whitehouse
BBC News Online science editor

Astronomers have detected what could be the Solar System's 10th planet.
Found further away than other planets by the recently launched Spitzer Space Telescope, it has been called Sedna after the Inuit goddess of the ocean.

Observations show it is about 2,000 km across and it may even be larger than Pluto, which is 2,250 km across.

There is likely to be debate about whether it qualifies as a true planet, but some astronomers are already saying it re-defines the Solar System.

The Hubble Space Telescope has also seen it.

Details will be announced by the US space agency Nasa later on Monday.

World of rock and ice

Sedna is the largest object found circling the Sun since the discovery of Pluto in 1930. Its size is uncertain.

One astronomer told BBC News Online that it may even be larger than Pluto itself.

It was found during the course of a survey led by Dr Michael Brown of the California Institute of Technology. Scientists are only midway through this three-year project.

Preliminary calculations suggest that it is 10bn kilometres from Earth in a region of space known as the Kuiper Belt (KB).

The KB contains hundreds of known objects and astronomers believe there are many more awaiting discovery. Most are small worlds of rock and ice but some, like Sedna, could be as large as or larger than Pluto.


The importance of Sedna is that it is the first such world discovered in its normal orbit. Other similar though smaller worlds, like Quaoar and Varuna, originated in the KB but have since been perturbed into different orbits.

Planet debate

Following the objects discovery astronomers at the Tenagra Observatory in Arizona were asked to provide positional information so that an orbit could be determined for Sedna.

The new discovery will reignite the debate about what is a planet.

One group of astronomers believe that Pluto is not a true planet but merely one of the largest of a vast number of minor objects in the outer Solar System.

The alternative standpoint is that Pluto is a planet and those who believe that will have to classify Sedna as the tenth planet.

[redstar2000]

I agree with the astronomers that say that Neptune is the outermost true planet.

Not only are Pluto and the other KB objects "too small" to really be considered planets but they also have wildly "unplanetary" orbits...something you'd expect of debris rather than orderly planetary formation.

If I'm not mistaken, it's thought that Triton, Neptune's largest satellite, is a captured KB object.

:redstar2000:

The Redstar2000 Papers (http://www.redstar2000papers.vze.com)
A site about communist ideas

[ÑóẊîöʼn]

I have to disagree, I believe Pluto and Charon to be a planet and moon respectively

The reason is thus;

Pluto is 2300 kilometres wide - wider than the largest known asteroid
It doesn't eject gasses like a comet
It appears to have a regular, smooth surface (Compared to an asteroid)

[MiDnIgHtMaRaUdEr]

What ever happened to *insert dramatic sound clip here* PLANET X!!!

[SittingBull47]

eh, Sedna's a bit iffy. I think it's just a big cold rock and we should concern ourselves with other celestial bodies.

[Xvall]

I think I don't give a shit about floating rocks that currently don't seem to conscern us in any way whatsoever.

[redstar2000]

Pluto as well as all the other KB objects thus far discovered are actually smaller than Earth's own moon.

The latest preliminary orbit of Sedna suggests a wildly eccentric orbit...it ranges between 90 billion miles and 900 billion miles from the sun.

There is at least one small asteroid that has an even smaller asteroid as a satellite...so having a satellite is not really a useful way to distinguish between a planet and debris.

Mercury, a small but fairly dense planet, has no satellite but is substantially larger than all of the KB objects.

Another useful way to distinguish between planets and debris is that all of the 8 true planets revolve within a plane extending from the sun's equator...suggesting a common origin. Pluto & the debris revolve in orbits that rise far above and plunge far below the sun's equatorial plane...suggesting they were "left over" from the original gas cloud.

If astronomers were like leftists, they'd form vanguard parties around this question and write fierce polemics against each other. :lol:

:redstar2000:

The Redstar2000 Papers (http://www.redstar2000papers.vze.com)
A site about communist ideas

[Xvall]

It's unfortunately true. If they were rightists, however, they would launch a pre-emptive strike against the orbiting moons which pose a danger to the gravitational balance of the galaxy, and might possibly be harboring weapons of mass destruction, as per out computer-rendered diagram.

[Vinny Rafarino]

Originally posted by [email protected] 15 2004, 02:08 PM
What ever happened to *insert dramatic sound clip here* PLANET X!!!
Good question....That one died out real quick. Perhaps they are one in the same.

[Stapler]

there are a number of small 'lesser' planets in our solar system, around the size of, or smaller than Pluto, the discovery of another one of them is hardly surprising.

[Cooler Reds Will Prevail]

Originally posted by Drake [email protected] 15 2004, 11:22 PM
It's unfortunately true. If they were rightists, however, they would launch a pre-emptive strike against the orbiting moons which pose a danger to the gravitational balance of the galaxy, and might possibly be harboring weapons of mass destruction, as per out computer-rendered diagram.
hahaha so true, so true........

in all honesty tho, who cares? its not like we're gonna move out there or anything....... what, we gonna be like "yeah bob, i'm thinking i might move to sedna, but i want to make sure its a real planet and has a consistent orbit around our sun"

:huh:

[MiDnIgHtMaRaUdEr]

I think that in order for a planet to truely be a planet, it needs to have an atmosphere with an average atmosphereic pressure greater then 0.5mmHg. That means that neither Pluto or Mercury are planets, and Saturn's moon Titan, and Neptune's moon Triton are. I think those two moons are more planet-like then either "planetoid". I say make Titan and Triton planets, and take out Mercury and Pluto.

[Exploited Class]

The new planet is just a way to improve the retail value of our solar system to other solar systems. Having another planet just increases the cost of property within our solar system.

"Come now and move to the SOL system, *NOW WITH AN ADDITIONAL PLANET*"

Add this in with a possible discovery of water, not just evidence of past water, on Mars and we will all be living on the sulphuric acid rich Venus due to rising housing costs within our solar system.

Also, my guess somebody very powerful and rich (Murdock) just purchased Selena, is looking for tourists and has tried to bump it up to planet statis to attract more people to it. "Come and relax to the very last planet in our solar system, see the solar system's largest ball of string".

[Cooler Reds Will Prevail]

Also, my guess somebody very powerful and rich (Murdock) just purchased Selena, is looking for tourists and has tried to bump it up to planet statis to attract more people to it. "Come and relax to the very last planet in our solar system, see the solar system's largest ball of string".

*thinks to self*

damn, mexicans comin up in the game.... we got a planet named after Selena!!

*walks out singin*
como la floooooooor.... con tanto amoooooor..........


:D

[Don't Change Your Name]

wouldn't that planet be Nibiru? that's the first thing that came to my mind when they talked about this on the news a couple of days ago.

[apathy maybe]

I was bloody disapointed when they didn't call it Rupert (see HHGG, by D Adams). There it is a 10th planet far out in the cold, just right for viewing what happens on Earth. (Before finially and absolutly ending the series once and for all by killing off the main charactors.)

[Dr. Rosenpenis]

I agree that it isn't a planet, and neither is Pluto.
Despite its planet-like shape and surface texture, it simply shouldn't be called a planet.
Yeah, it's bigger than otehr asteroids, but it's still pretty damn small.
I'm sure there are loads of perfectly round and smooth asteroids in the huge astroid belt. That thing contains thousands of rocks, some of which are likely pretty big and round.

And as redstar mentioned, the 8 planets move in relatively equatorial orbits around the sun.
These otehr rocks are much further out and don't have a proper orbit.

I suggest that once we discover the date of the creation of the solar system, we must determine which planets were created around that time, and any other ones will be assumed to simply have been caught in the sun's gravity field and therefore not an actual planet.

On a side note, I also suggest we move thsi thread to the Science forum. The capitalists can shove it.

[MiDnIgHtMaRaUdEr]

Hey! I'm not a capitalist, and I'm pretty damn interested in the subject! What does everyone think about classifiying Titon and Triton as planets? The atmosphere thing seems cut and dry as far as classifying something as a planet or not.

[Dr. Rosenpenis]

My idea is better and also very cut and dry.
Clearly you are not fit to discuss and belong where only vulgar crap is debated.
Move this thread immediately!
Just kidding, keep it here. Who cares.

[MiDnIgHtMaRaUdEr]

Yeah, too bad I can't talk in the other sci and env threads though. For the most part, politics are irrelevant in those threads anyways.

[DarkAngel]

hmm if its frozen wouldnt that mean there must be water. uuuu new life?

[redstar2000]

hmm if it's frozen wouldn't that mean there must be water?

Possibly, but frozen methane is more likely.

It's about 400 degrees F below zero on Sedna...which means every gas would be frozen except hydrogen (which is too light to be retained by Sedna's very weak gravity).

There might well be some frozen nitrogen or frozen ammonia there as well.

The orbital period of Sedna is estimated to be 10,000 years (Pluto's is 250 years). A long time between New Year's Eve parties. :lol:

:redstar2000:

The Redstar2000 Papers (http://www.redstar2000papers.vze.com)
A site about communist ideas

[Spartacus2002]

a new planet yeeaaaaaaa.... i wonder when bush will want to go to this one by the way how many people are starving in africa

[redstar2000]

by the way how many people are starving in Africa

In the eyes of Mr. Bush, Africans are not "people"...so your question would make no sense to him. In his world, the only real people are people like him.

With our current technology, a planetary probe sent to Sedna would take about 150 years to get there.

:redstar2000:

The Redstar2000 Papers (http://www.redstar2000papers.vze.com)
A site about communist ideas

[Rastafari]

Originally posted by [email protected] 21 2004, 11:57 PM

by the way how many people are starving in Africa

In the eyes of Mr. Bush, Africans are not "people"...so your question would make no sense to him. In his world, the only real people are people like him.

With our current technology, a planetary probe sent to Sedna would take about 150 years to get there.

:redstar2000:

The Redstar2000 Papers (http://www.redstar2000papers.vze.com)
A site about communist ideas
Exactly. If you look into his AIDs money he promised in the State of the Union, you'll see that very little, if any, has made it there.