Hey Everyone,
Nasa's Dr. Michael Brown of the California Institute of Technology is going to announce today at 1:00pm est that it has found a 10th planet in our Solar System! Sedna, a Kieper belt object 2000km in diameter 300km less than Pluto is 10billion km from Earth. There is debate that Pluto should not be a Planet! but those who say IT IS will surely want Sedna to be our 10th!! it was found by the NEW 'Spitzer' space telescope, and confirmed by the Tenagra Observatory in Arizona!!
So lets have a little debate here is it a planet? is Pluto? OH and does it sound like ANY RB story anyone has read??!!!

John AJ

I saw the news item on the possible discovery of a 10th planet. Pretty exciting. Between that that the Hubble shots and the Mars Rovers, it's a pretty exciting time to be alive -- in terms of a knowledge explosion about space.

I grew up being told Pluto is a planet, so I'm going with that until I hear otherwise. What is the astronomers' definition of a planet? Is there some official critieria listed and accepted by scientists as the "rules"?

I'm not aware of anything like this in Bradbury. He did one story ("The Square Pegs") about asteroids being used to house the terminally insane. Each asteroid would be constituted to meet the needs of a "troubled" person. If someone thought, for example, that they were the Queen of England, the asteroid would be peopled in a way that supported that particular illusion.

One definition of a planet is an object orbiting a star that is not a brown dwarf but bigger than an asteroid. Of course, there are many other definitions. I have always been taught that Pluto is a planet as well, but I have read that most mainstream scientists agree Pluto never should have been called a planet.
The main reason for this debate, that I have heard, is the fact that Pluto roams so far beyond the orbit of Neptune that researchers say it is actually part of the Kupier Belt. This is just a region of distant, frozen rocks.
I'll probably just go on thinking of Pluto as a planet though.

Mr. Dark,
Most of the scientific definition of a planet is a rotating space body with an electro magnetic field, and an atmoshpere. The Earths magnetic field is what protects us from harmful Solar radiation! Pluto has an atmoshpere and barely an eletromagnetic field.
But like the Martian field it is also broken and scattered, with multiple north and south poles. Our electromagnetic is not in line with our axis, in fact it is moving and has flipped once in the distant past as the Suns does every 11yrs. as part of the Solar cycle.
Ganymede one of Jupiters moons also has a complete magnetic field and being about the same size as Mercury it can be called a planet in its own right!!. It also has a subsurface ocean just as does Europa and (thanks to the Galileo probe) we know also does Calisto. Those are the three of the four largest moons of Jupiter. Io the last of the four (visible with 16x50 binoc's) is the most Volcanic body in our Star System.
JIMO (Jupiter Inner Moon Orbiter) the next NASA probe to go to Jupiter will study three subsurface ocean Moons!! It will also be designated 'Prometheis' our first Nuclear engine in space!! It will get in 1/3 the time of any probe so far!
Did you know we have already tested and flown our first Ion engine!! Deep Space 1 is now a time capsule in orbit around the Sun!! It is the fast manmade object ever, reaching 84,000 mph!! For more info go to http://jpl.nasa.gov

John AJ

Very neat stuff.

It's about time, it's about space, it's about time they found that place!

About pluto: If the new planet is smaller in diameter than pluto, then will it really be a planet (there are many large asteroids in the Oort cloud that can rival pluto's size)? Jajboeg, you seem to be an expert, explain.
Cheers, Translator

Have they figured out yet if it's larger than or smaller than Pluto? I keep reading both. One article said about the same size; one said about 40% of Pluto's size; one said "larger than". Can they figure that out, yet?

Since this new "planet" is really a planetiod, I am not too excited. Watch for the big one that Zecharia Sitchin wrote about in the his "Earth Chronicles" books. Should be detectable any year now, if they are really looking for it. One person at the Naval Observatory was said to have evidence of its presence, but then he myteriously stopped talking. It is on an excentric orbit that takes it way beyond the orbit of the known outer planets, with an obrit that takes 36oo years to complete.

Translator,
Well when I heard Miles O'Brien say it was in the Oort cloud I freaked!! An Orbital year 10,000 Earth years long WOWser!!! The Oort cloud is over 50 AU away. If it has an Atmosphere its frozen solid like Pluto's has been for most of the time we've known it.
Consider we've known of Pluto about 70yrs, it just finished summer when its atmosphere was thawed so any probes now won't learn much.
What makes a planet a planet is a molten core that rotates at a different rate from its crust causing a dynamo effect and making its electro magnetic field. That field creates a force shield bubble that protects the planets atmosphere from the UV radiation of the Solar wind! Without that we'd all burn like we were standing next to a nuclear explosion.
Did you ever sprinkle iron filings around a bar magnet in school, those curved lines are the bubble around Earth. And they curve in at the poles, where the Solar wind streams down and reacts with the atmosphere. That reaction gives off light that we call the Aurora Borialis at the North pole and A. Australis at the South pole!
That reaction is called Ionazation its the same thing that is going on in your TV cathoray tube right now...Whoa Whoa Whoa I digress and this is no time for a science class sorry.
Size in SOME cases has little to do with it but a moon like ours is 1000miles in diameter; if it had a molten core, eletromagnetic, and atmoshpere it could be a planet. But you need MASS which would make gravity enough to KEEP that atmosphere. Thats why a comet is a comet, because it only has an atmosphere when it gets close to the Sun. and without gravity it blows away in the Solar wind thats called its tail.
The tail ALWAYS points away from the Sun so in the comets orbit when its leaving the Sun and headed back for the Oort cloud its flying INTO ITS TAIL, OH yeah oh yeah believe it or not!!...Ain't Astronomy COOL!!!!! Now I'll wait for the NONbelievers to CHIME in!!!

John AJ

Sedna is 2000km in diameter, Pluto 2300km Hubble and the New 'Spitzer IR space telescope have found and measured it!!!

John AJ

[This message has been edited by jajboeg (edited 03-15-2004).]

The Sednan Chronicles.

It's a planet. We can't get too uppity about size (what is our preoccupation with "size matters?"). Very exciting indeed. I am sure we will be discussing it in my astronomy class this week. I'll keep you posted on our classroom discussions and what the profs have to say.

Since many scientists think the solar system doesn't just abruptly end...but contain many such 'Sedna's' ...
I kinda like the name they call them all: """"" Planetessimals !!! """""


[This message has been edited by Nard Kordell (edited 03-16-2004).]

Prof. Greentown,
You truely are the expert!. Do I have those descriptions right?? And do you think Ganymede should be called a planet?

John AJ
P.S. Oh, are you the prof. or the pup.?

Whoops! I didn't mean to mislead you, jajboeg. I'm taking an astronomy class (a couple actually) and I have several professors. Prof. Greentown does have a nice ring to it, though. Sounds like a comic book villain.
I don't think Ganymede or any of the other Jovian Moons are planets because Jupiter is not a star. Moons can support life and "act" like planets and still be moons.