Why are the Planets almost round?

[Pete999]

Go on take the Mick not bothered, I couldn't sleep last night so I got up and started watching some NASA documentary's, one described how some Scientists reasoned that the Earth and the Moon, along with other planets within our Solar System, were created by giant collisions millenniums ago, so to my question, how come Planets areas near spherical as you can get for something as big as they are, surely if they were created by collisions they would be ragged in appearance, but most appear to be spherical, what do you all reckon? A bit deep for an early morning thread, but hey ho.

 

[Octopus]

Gravity.

 

[Bob Geldoff1234]

I am no expert but I would think it's something to do with the earth being molten in it's early life and the earth spinning at a very fast speed.Everything gets thrown outwards into a perfect circle as it spins.

 

[Midwest]

They're not round, they're flat

 

[telectrix]

you're all wrong.

 

[Spoon]

you're all wrong.

View attachment 43741

Love minecraft... but that's taking the thread off at a tangent again....

 

[Pete999]

They're not round, they're flat

Right!!!!!!!!!!!

 

[telectrix]

Love minecraft... but that's taking the thread off at a tangent again....

that's the answer to pete's question. it's to provide tangents that makes the planets round. only a circle has tangents.

 

[rsgaz]

Everything gets thrown outwards into a perfect circle as it spins.

More like, these is so much mass, that everything gets crushed into a sphere. Doesn't really matter if it's spinning or not.

If there is enough mass to create enough pressure and heat to turn the middle into liquid, it will squidge* into a sphere under it's own weight.

* squidge = highly technical term!!

 

[Pete999]

More like, these is so much mass, that everything gets crushed into a sphere. Doesn't really matter if it's spinning or not.

If there is enough mass to create enough pressure and heat to turn the middle into liquid, it will squidge* into a sphere under it's own weight.

* squidge = highly technical term!!

Kin Hell a few Nobel Prize winning theories floating about today. Especially the "squidgy " theorem, love it.

 

[Squid]

Mercury and Venus are the roundest, near perfect spheres, now why are planet different colours and what about hypervelocity?

 

[The Ghost]

That's the way God made them.

 

[littlespark]

Not perfectly spherical. Fatter round the equator as the spinning pushes it out.

A bit like a builder after too many times on a merry go round

 

[Midwest]

Right!!!!!!!!!!!

I was listening to the Vine show some time ago. There were several believers explaining their theories. As to the edge of the world issue, apparently there's a massive ice wall, thats stops you falling off. Its located in Antarctica. Thats why the worlds main protagonist won't allow public access there. And the reason you see the curvature of the world from an airliner, is the pin cushion effect of the aircrafts windows

 

[Deleted member 26818]

Planets form by particles attracting each other due to gravity.
They form a sphere because the attraction operates in all directions equally.

 

[telectrix]

but the earth is not a sphere. it's a jagged lump. it's only
round because water has filled most of the holes.

 

[littlespark]

Jagged lumps due to parts of the crust around the planet pressing against each other and being pushed up.
Also volcanic spouts of molten lava solidifying and creating mounds.
All this happens over millions of years and is hard for us to imagine.

A bit like waiting for a plumber to arrive

 

[telectrix]

 

[GeorgeCooke]

Surface tension.

 

[ElectroChem]

@rsgaz has it essentially right.

Any planet/planetoid of larger diameter than ~1000km (IIRC) will form a roughly spherical shape as its own weight is enough to overcome the rigidity of rock/iron-nickel so it 'squidges' together.

@telectrix

The earth is jagged to our perception, but in terms of the surface roughness vs overall diameter it's about as smooth as a billiard ball.

 

[Andy78]

They're not round, they're flat

Apparently flat earthers accept that all other celestial bodies are generally spherical, just not ours.

 

[JAWS]

Go on take the Mick not bothered, I couldn't sleep last night so I got up and started watching some NASA documentary's, one described how some Scientists reasoned that the Earth and the Moon, along with other planets within our Solar System, were created by giant collisions millenniums ago, so to my question, how come Planets areas near spherical as you can get for something as big as they are, surely if they were created by collisions they would be ragged in appearance, but most appear to be spherical, what do you all reckon? A bit deep for an early morning thread, but hey ho.

While you were watching that Pete I spent the hour watching a documentary about James Clerk Maxwell & electromagnetism

 

[Pete999]

While you were watching that Pete I spent the hour watching a documentary about James Clerk Maxwell & electromagnetism

Must watch that

 

[Ian1981]

You should download the series called ‘one strange rock’
10 part documentary narrated by will smith but with astronoughts giving the scientific facts about various different subjects.

 

[static zap]

The earth bulges at the equator , and the moon is un-even enough to always be pointing the same way towards us, due to gravity (Displaced c-o-g )
... Dark side of moon moment.
Gravity and the efficiency of maths - smallest volume is a sphere.
..Random thought= Solder Balls..

 

[Intoelectrics]

A little interesting fact for you,

The "gas" giant Jupiter has a layer of hydrogen & helium gas which is so dense under the immense pressure that it has formed an ocean of liquid metal.
The giant red spot is an immense storm in the atmosphere that they believe has been raging for hundreds-thousands of years. The spot is larger than the Earth!

In answer to Pete, in layman's terms, mass is always attracted to the centre of gravity. At some point the surface tension will give up under the immense pressure from the weight of the mass so the object settles into a sphere because that is the only natural shape where any point on the surface becomes roughly equidistant from the centre of gravity.
Hydrostatic Equilibrium:
In astrophysical terms, hydrostatic equilibrium refers to the state where there is a balance between the outward thermal pressure from inside a planet and the weight of the material pressing inward. This state occurs once an object (a star, planet, or planetoid) becomes so massive that the force of gravity they exert causes them to collapse into the most efficient shape – a sphere.

Typically, objects reach this point once they exceed a diameter of 1,000 km (621 mi), though this depends on their density as well

 

[telectrix]

i've watched a few episodes of "Drain the Oceans". I wonder how well their wet/dry vax will work with a wall chaser.probably suck all that nasty dot&dab away into outer space where it should be.

 

[buzzlightyear]

now I will throw a spanner in the works ,if this planet was mouton rock to hot and cooled down .where do the water come in to it .now think about it .

 

[JAWS]

now I will throw a spanner in the works ,if this planet was mouton rock to hot and cooled down .where do the water come in to it .now think about it .

Is Mouton not the French word for sheep

 

[littlespark]

10 part documentary narrated by will smith

Will Smith the Fresh Prince of Bel Air?

where do the water come in to it .

Fish pee?

 

[Spoon]

Is Mouton not the French word for sheep

I'm confused now.... So instead of this flat Earth being carried by a turtle it is actually being carried by a sheep???

 

[Des 56]

The moon is always pointing its one side to us because it turns one revolution in the same time as it takes to orbit the earth

The really cool and handy coincidence is that the moon is 240 times smaller than the sun but is 240 times closer
Anyone like watching a total eclipse

 

[telectrix]

how do you watch a total eclipse? it's bloody dark.

 

[Intoelectrics]

now I will throw a spanner in the works ,if this planet was mouton rock to hot and cooled down .where do the water come in to it .now think about it .

Hi Buzz, in what sense are you asking?
matter tends to come in 3 basic forms - gas, liquid and solid. Water (H2O) can be found naturally occurring on earth in all 3 states, steam, water, ice. Water forms when 2 hydrogen gas molecules interact with 1 oxygen molecule within in the right environmental conditions, hence H2O.
One of the things scientists look for on other worlds in and beyond our solar system is the signs of water, preferably liquid water because it appears that it is essential for life as we know it to exist. meaning there could be a possibility of life forming there - E.T

 

[telectrix]

and bung some carbon in with the hydrogen and oxygen, shaken , not strirred, and you have life. so it's back to fish again.

which leads to the question:
Q. what do you call a fish without an eye?

A.FSH.

 

[Des 56]

how do you watch a total eclipse? it's bloody dark.

You experience the event,like savouring a cracking pint

Its like someone said on here before "no such thing as a Light emitting lamp"
The confusion is because its really just a "dark sucker"

 

[telectrix]

and planets are not different colours. they just reflect different wavelengths.

 

[Spoon]

and planets are not different colours. they just reflect different wavelengths.

So what colour is Uranus????....

 

[telectrix]

So what colour is Uranus????....

mines a sort of reddish pink with a black hole in the middle.

 

[littlespark]

Too much information, Tel