Why are the planets round?

Question

why are they not square or triangular or jus plane, well, rocky looking?

please, dont bore me with your patronising answers bunch of toffs (no offense to those who answer seriously and are not rude cuz im gettin bored now)

Answer 1

Gravity pulls them into an oblate spheroid. As most bodies form as a semi-liquid or dust accretion the new matter will tend to fall downhill towards the centre of gravity, hence forming a spherical shape as the mass increases

(In fact the definiation of a planet says of a mass capable of forming an oblate spheroid. Therefore an object that isn't an oblate spheroid isn't of sufficient mass, and therefore isn't a planet).

Answer 2

Because spheres are special, like no other shape.

The shapes of planets are spheres because the sphere is the shape you get when the race is a tie. Each piece of the planet tries to get to the center. A really really long time ago the heaviest pieces of our planet which are made of metal, not rock, won this race and they are now at the center of Earth, metal wins over rock. But each piece of rock that makes up the rest of the planet is still trying to win the race and because most of them are pretty much the same it comes out a tie, and the shape of a tie is a sphere. So planet's are spheres because the sphere is the shape you get when no one piece of the planet is much different from any other and all the pieces are trying to reach the center. Why do the pieces of a planet try to reach the center, I'm sure you know, it's the force of gravity.

Some little moons, like the moons of Mars, and most asteroids don't have enough gravity to start the race to the center. In those cases the shapes can be very bumpy, even like a potato.

Answer 3

Well Alistairwauchope made a good point there. Its really a combination of all of the above. When a planet is formed, gravity pulls in all available 'rubble' from the surrounding space. The bigger the mass of the planted the stronger the field of gravity, which is distributed evenly over the whole surface - but, because the planet is spinning it creates a centrifugal force which acts against the pull of gravity at the equator of the planets creating a slightly flatter shape.

Answer 4

Hot, churning, burning gas swirls itself into a huge spinning nebula. It spins itself up like cotton candy on a stick, or, wool on a spindle, chubbier in the middle. As the gas cools a tad, the chubby bulge in the middle of the stick, or, invisible axis, sort of draws up unto itself and the more spherical form begins to appear. Still hot, it's now a star. Sometimes, hot, gaseous and molten matter breaks off from the spinning star as it's forming, like cake batter splattering everywhere with an electric mixer. The big blobs almost, but not quite, escape the electromagnetic tentacles from the sun that are whipping around with the sun and that hold the blobs, or, new planets, enthralled, in her gravity. Those trapped blobs, as they cool, pretty much undergo the same kind of "cotton candy on a stick formation sequence" as did their mother sun. That's why planets are round.

Answer 5

Spinning through space at a very high speed tends to cause them to conform to a round shape. Planetary rotation causes erosion which approximates roundness. Core gravity also plays a role in this function. Newer planets are less round than older ones, presuming they both have atmospheres.

Finally, because it looks really cool that way, and results in the best aerodynamics for a rotating body.

Oh, and by the way, the earth is kind of ovate.

Good luck

Answer 6

Planets and other fairly large bodies tend to have a spherical shape because their gravity is able to surpass the structural force of the substances (rock, gas, etc.) that compose its makeup. Gravity tends to squeeze matter into the smallest volume possible, and that shape tends to be a sphere. In fact, the actual term is oblate spheroid, since planets tend to bulge at the equator due to rotation. In smaller bodies like earth, this isn't very noticable. However larger bodies, such as stars and gas giant planets (such as Jupiter and Saturn) this effect is more apparent.

Answer 7

Try swirling a cotton candy around its stick as fast as you can and you will soon discover that it will become as round and smooth as possible. This is because of the rotating motion and the not so rigid state of the cotton candy.
Putting this analogy into the roundedness of the planets: the rotating motion of the planets around their axes and the fluid state of the these heavenly bodies resulted, after eons of years, of them not being triangular or just plane.

Answer 8

It is because of gravity, as most others have said. Planets are formed by accretion of generally small pieces. They build up. As a planet gets very large gravity will effectively tend to even the shape out. Another aspect, not apparently mentioned alredy, is that they are formed from material all around them, and so are pulling that material iin from all directions, roughly equally. This will naturally tend to produce a largely round object. (I think)

Answer 9

Due to Heat force of attraction and the theory of relativity to be precise, check these three and a Little common sense:)
You shall also find out that any body resulting in, formation will never be round but rather egg shape...Nature is all the same....think about anything and you will be amazed that they are related....

Answer 10

Because the fabric of space make them round as the roll along it it wears away the bits the stick out. Not been funny but why ask if you dont want to know the answer.