Why are planets ball shaped...

Max Headroom

Anyone give me a simplified explaination.....:o

Hauk

Hi Max,

http://curious.astro.cornell.edu/question.php?number=19

That should be perfect for you.

emobama

I'm not sure what that information was at the other end of the link, 'because i'm lazy' but to simply answer the question, Why are planets round'
It's because of gravity, when all the planets were formed they pulled in material floating about in space and this material was pulled in evenly around each planets gravitational pull or core, Earth has an active molten core for example, that is the source earths gravity.

I thinks Pluto has an unusual shape, but then Pluto a been demoted to a dwarf planet!!

Simples!!!!

Caoimhín

emobama wrote: »

Earth has an active molten core for example, that is the source earths gravity.

Simples!!!!

Huh? you sure about this?

emobama

Sure about which part, the molten bit?

Caoimhín

emobama wrote: »

Sure about which part, the molten bit?

Well yeah, the molten bit being the source of gravity.

emobama

kinda sure, I'm not saying it's because it's molten or partly molten that creates Earths gravity?!

I would believe that the source of gravity for a planet like ours is it's core, our core might be solid surrounded by molten iron and nickle, or the whole core could be molten, either way there are reactions happening down there which create magnetic fields and also result in gravitational pulls, but who knows for sure what down there.

The moon has a gravitational pull, so where is that coming from, well most likely from a solid, once molten core.?

Gas giants such as Jupiter has huge gravitational influence over it's own system but the strong magnetic field around Jupiter is created by the flow of electricity through the metallic hydrogen.

What ye reckon?

Caoimhín

http://en.wikipedia.org/wiki/General_relativity

emobama

Humm, there is a lot of reading there!

What does it say? is that contrary to my concise version of gravitational sources?

.

Caoimhín

Its a bit early to start explaining the theory of general relativity, im having a few drinks tonight so i will get back to it then, mmkay?

emobama

Ten - Four!

COUCH WARRIOR

hi max

I think hauk's link should give you what you want. Never mind Caoimhín's general relativity canard, he's just thrown that in there to avoid owning up to his misstatement.

loosely all "stuff" has a gravitational attraction to other stuff. The earths gravity is the combined gravitational attraction of all the stuff that the earth is made of.

It pulls us towards the core, but every bit of the earth adds its part to the over all gravity of the planet.

Adding in the moon, the sun and the earth's spin all complicate the picture and give rise to the tides but I'm getting carried away.:rolleyes:

CW

Beeker

COUCH WARRIOR wrote: »

hi max

I think hauk's link should give you what you want. Never mind Caoimhín's general relativity canard, he's just thrown that in there to avoid owning up to his misstatement.

loosely all "stuff" has a gravitational attraction to other stuff. The earths gravity is the combined gravitational attraction of all the stuff that the earth is made of.

It pulls us towards the core, but every bit of the earth adds its part to the over all gravity of the planet.

Adding in the moon, the sun and the earth's spin all complicate the picture and give rise to the tides but I'm getting carried away.:rolleyes:

CW

The way it was explained to me is that like CW said all mater has a gravitional pull on all other mater. Small objects like asteroids can be any shape like a peanut or even square because they dont have enough stuff for gravity to pull hard enough to make a "ball shape". It is only when you reach a critical mass that gravity is strong enough to pull everything into a ball. That is the shape that naturally forms from all the mass trying to get to the center. Now iknow the earth is not exactly a ball with mountains and valleys but on the grand scale it is.

Caoimhín

COUCH WARRIOR wrote: »

hi max

I think hauk's link should give you what you want. Never mind Caoimhín's general relativity canard, he's just thrown that in there to avoid owning up to his misstatement.

CW

Where exactly is my "misstatement"?

Turtwig

Caoimhín wrote: »

Where exactly is my "misstatement"?

Think you were confused with Emobama's musing.

Turtwig

Well I completely borked that last post. (Mixed up fora:o)
Anyways, OP, here is something that, well, most of us here are Sagan fans so you ought to watch his entire series. Will answer a lot of questions for you. Also, if these are the kind of questions you ask yourself, then check out the Last Word section in Newscientist, AskaScientist. and books like "Do Polar Bears Get Lonely".

Phil Plait also explained in an excellent series of videos for kids.

Also don't hesitation to post your queries here either.

Caoimhín

Malty_T wrote: »

Think you were confused with Emobama's musing.

What? ye are all fecking mad in this thread. I suppose the earth will be flat next?

Turtwig

Caoimhín wrote: »

What? ye are all fecking mad in this thread. I suppose the earth will be flat next?

???
I was just say CW mistook Emo's post for yours.