Why are planets round?

Hi everyone,

I am not sure if any of you have ever asked is question,"Why are planets round?". Well, even if have never asked this question, heres the answer anyway.

ANSWER:

gravity, since it is even on every side of the object, in this case the planets core, there is an equal amount of gravity pulling in mass on all sides which is why the atmosphere is a constant distance from gound even the surface is so unsmooth.


Answer
Gravity is the key. You may be aware that Jupiter, our largest planetary neighbor in the solar system, is almost all gas (there is a small core of non-gaseous material). Understanding that Jupiter is a ball of gas, wouldn't it be bizzare if it had a shape other than a sphere? Think also of a bubble blown by a child (or your inner child) through a loop. Even very large ones (which are the most fun) seem to seek rest in a spherical shape, even if breezes batter and deform it from time to time. Matter seems to seek to balance internal forces. It would be scary to look up at Jupiter and discover that it had morphed into a doughnut shape or a large tube shape.

When we are talking about collections of matter that are planet-sized, the same general idea holds. Taking a mass equal to that of the earth, and of similar materials, you could attempt in your mind to construct a pillar with a 1,000 kilometer diameter. But you wouldn't get too far before the pillar's mass would exert so much gravitational force that the whole thing would come crashing in. Even if you braced the pillar while building it, the inner sections would eventually crumble and/or melt long before you finished. Eventually, all the mass would find its way to balance out the gravitational forces.

FROM: http://wiki.answers.com/Q/Why_are_planets_round

Till the next new fact,
May