Why are the Planets almost round?

[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?