What Is A Planet?

[Gypsyfly PMS]

I thought I knew, and I most certainly thought astronomers and other scientist would know the answer to what seems a very simple question.

Well, I have to admit any definition you find of the word "planet" is usually pretty vague.

I was reading Readers Digest when I saw this story:

CNN--Earth's moon could become a planet (http://edition.cnn.com/2006/TECH/space/08/18/moon.planet/)
SPACE.com--What is a planet? Debate Forces New Definition (http://www.space.com/scienceastronomy/solarsystem/planet_confusion_001101-1.html)

Apparently, because our definition for the word "planet" is so crappy...some scientist our going to vote on pretty much making anything that floats in the air a "planet" including a few dwarf planets, Pluto's moon, an asteroid and hey they may even throw in a satellite while they're at it.

Basically, they want to come up with a definitive definition for the word planet:

Finding a textbook definition for the word "planet" is tricky. Amazingly, many science and astronomy books -- just like the IAU -- don't define the word. You won't find a basic definition in the New York Public Library's Science Desk Reference, for example. And in the 1999 edition of Universe, a comprehensive tome used widely in college courses, "planet" is not even an entry in the 21-page glossary.

How could this be?----Robert Roy Britt, Space.com

This is all fine, except that they're definition doesn't improve matters.

-- If astronomers approve a newly proposed planet definition next week, things could get really strange. Sure, asteroid Ceres will become a planet. Pluto's moon Charon will become a planet.

But we're talking really strange.

Eventually, if Earth and its moon survive long enough, the moon will have to be reclassified as a planet, said Gregory Laughlin, an extrasolar planet researcher at the University of California, Santa Cruz.

The new definition, proposed this week by the International Astronomical Union (IAU), basically says every round object orbiting the sun is a planet, unless it orbits another planet. But there is a big caveat: If the center of gravity, called the barycenter, is outside the larger object, then the smaller object is a planet. That wording elevates Pluto's moon Charon to planethood, an idea some astronomers have criticized.----Robert Roy Britt, Space.com

Haha, imagine having to memorize more than 53 "planets". That would make those Styrofoam planet projects a pretty big pain to carry.:p

[xi Apocalypse ix]

Gypsy, maybe this will help: http://en.wikipedia.org/wiki/Planet

[PMS Kahlo]

I saw something about this the other day. And yes, with their new definition of what a planet is, we could be seeing many more being named! I think they are talking about adding at least 2 more "planets" to our solar system.

[Gypsyfly PMS]

Gypsy, maybe this will help: http://en.wikipedia.org/wiki/Planet

Hehe, same definition no matter where you look Fusion. Hopefully, they come up with something actually useful.

[xi Apocalypse ix]

Hehe, same definition no matter where you look Fusion. Hopefully, they come up with something actually useful.
Yes I know, I wish NASA will discover something like Halo:D . That would be cool.

[Buddy H2O]

Yes I know, I wish NASA will discover something like Halo:D . That would be cool.

rofl. Um yeah so anyways i think its pretty weird how they dont have an acual definition of planet. Pretty stupid IMO.

[H2O Tyrant Sparda]

i have my defanetion on a planat, and it is, a round object in space, and it has its orbit
and some moons, and ya, thats basicy it :) :cool: :D

[Gypsyfly PMS]

i have my definition on a planat, and it is, a round object in space, and it has its orbit
and some moons, and ya, thats basicy it :) :cool: :D

Haha, you and the astronomers have the same idea.

[Xenos]

thats hardcore craziness right there

[PaulPool]

Yes, I remember a show with this guy who does not have Pluto in his museum. He got a lot of hate mail.

And the current deffinition of a planet would mean adding a whole lot of planets. So for now it's undecided, and pluto is included in most maps.

[Kal-El]

I saw something about this the other day. And yes, with their new definition of what a planet is, we could be seeing many more being named! I think they are talking about adding at least 2 more "planets" to our solar system.


I heard that with their new definition out solar system could go from 9 to 12 planets.

[H2O Ninjitstu]

There seems to be a bit of confusion about what makes a planet and how you can define one. I heard recently that some astrologists don't acknowledge Pluto as a planet because they think it's too small, so that would change how we view our solar system. I wouldn't say I'm an astrologist but I do like documnetaries about space and mysteries within the multi-verse.

Very interesting topic Gypsyfly

[asphix]

Interesting.. but I think its all just being nit picky if you ask me.

We should actually try to reach said planets before looking to re-define the qualifying criteria in order to add more to the list.

Course it really doesnt hurt anything so what the heck.

[Dizzydude]

It's like trying to redefine the music genre's. Yea some of them may not fit exactly or make sense, but it works.

[H2O Ninjitstu]

According to BBC News (UK) Pluto has now been downgraded from a planet to "space rubble". The former 9th planet in our solar system (only the size of North America) has been considered too small to be a planet as I said in my previous post. Get yer textbooks re-written as it's official we now have 8 planets in our solar system as it stands.

Interesting stuff. http://news.bbc.co.uk/1/hi/sci/tech/5282440.stm

[H2O Tyrant Sparda]

Haha, you and the astronomers have the same idea.

Really! yey for me i can be an astronomer if i wanted, ahaha im on top of the world!
"On to of old smokeyyyy, all coverd in cheeese, I lost my to loverrrr the meat ball with cheeese:D " thats my edited ver:cool:

[Kal-El]

i have my defanetion on a planat, and it is, a round object in space, and it has its orbit
and some moons, and ya, thats basicy it :) :cool: :D

With that definition there would be 1000 "planets" in our solar system. There's an asteroid field in the solar system. By your definition all the asteroids could be planets too. They're coming up with a new definition to prevent that confusion from happening.

[H2O Tyrant Sparda]

With that definition there would be 1000 "planets" in our solar system. There's an asteroid field in the solar system. By your definition all the asteroids could be planets too. They're coming up with a new definition to prevent that confusion from happening.

who cares. basicly what i think, i planet is round, has a core, has gravity, has revoles around a star, such as our sun, has an atmosphere, and has atleast one moon, and why does your avatar say eh holes eh.:cool: thats very insulting. i live in canada ya know

[Kal-El]

who cares. basicly what i think, i planet is round, has a core, has gravity, has revoles around a star, such as our sun, has an atmosphere, and has atleast one moon, and why does your avatar say eh holes eh.:cool: thats very insulting. i live in canada ya know

Obviously you don't care because compared to them you don't have a clue what you're talking about.

Very few of the planets in our solar system have what's you'd call an atmosphere. Heck by your definition even the Earth wouldn't be considered a planet. Since the Earth isn't exactly round. Even our moon could be considered a planet according to your definition. All it's lacking is it's own moon, since it's round, goes around the sun (it follows the Earth around), and it DOES have an atmosphere!

See why they had to change the definition? Because the one they had (yours) doesn't work.

BTW: I just ate a kitten.

[H2O Default]

Well I read somewhere (newspapaer, maybe?) that a planet had to accomplish three things

1) It had to have enough mass to make the gravitational pull force into a sphere shape.

2) It must orbit the sun
and...

3) It must clear out everything in its path of orbit. (which is what pluto has apparently failed to do.)

IMO they actually think is just too small but most give the reasoning stating that since pluto only manages to complete an orbit about every 265 (earth) years, which would mean it hasnt completed an orbit since it was dicovered in the 1930's, it cant possibly clear out everything in its path... Please don't flame me for their reasoning, I'm far from being a NASA employee...

[Kal-El]

Well I read somewhere (newspapaer, maybe?) that a planet had to accomplish three things

1) It had to have enough mass to make the gravitational pull force into a sphere shape.

2) It must orbit the sun
and...

3) It must clear out everything in its path of orbit. (which is what pluto has apparently failed to do.)

IMO they actually think is just too small but most give the reasoning stating that since pluto only manages to complete an orbit about every 265 (earth) years, which would mean it hasnt completed an orbit since it was dicovered in the 1930's, it cant possibly clear out everything in its path... Please don't flame me for their reasoning, I'm far from being a NASA employee...

Well the part about the sphere shape is wrong. Even planet Earth isn't spherical. This is due to a phenomenon called "rotational flattening." Planet Earth looks more pumpkin shaped.

As far as I know Pluto is still considered a planet. They just reclassified it as a "dwarf planet." Which makes sense. It is small hence the term dwarf.

The more we learn about the universe and how it's formed, the more our current terms become out-of-date. New terms need to be thought up to classify things into narrower fields that better describe the objects out in space. Contrary to what some people might believe, they're not doing this just because they're bored and need something to do/will get their names in the paper.

[H2O Tyrant Sparda]

Obviously you don't care because compared to them you don't have a clue what you're talking about.

Very few of the planets in our solar system have what's you'd call an atmosphere. Heck by your definition even the Earth wouldn't be considered a planet. Since the Earth isn't exactly round. Even our moon could be considered a planet according to your definition. All it's lacking is it's own moon, since it's round, goes around the sun (it follows the Earth around), and it DOES have an atmosphere!

See why they had to change the definition? Because the one they had (yours) doesn't work.

BTW: I just ate a kitten.

yup, you never stoped being an eh hole yourself:D

[Sigrdrifta]

If pluto isn't a planet anymore, where will we get plutonium?

[H2O Default]

If pluto isn't a planet anymore, where will we get plutonium?

I see a dark time in store for our future...

And when i said 'sphere shape' i wasnt actually meaning geometrically... simply that it has to follow a certain suite...