Planets, star???????

Question

why all planet , stars, and moon are round? thanks

Answer 1

a sphere is the 3D shape that encompasses the most volume with the least surface area.   Gravity pulls everything in towards the centre, and the shape that gets the most mass closest to the centre is this shape.  

(of course spin changes things a little, but not very much)

Answer 2

Because squares would look funny on a map.

Answer 3

simply same reason stones on seashore are rounded. due to water washing over them after time they become smooth and round- planets have wind flowing over them and particles over them and after time they are round.

question is what shape did they begin as???...................

Answer 4

Gravity, Gravity, and I repeat Gravity! Things are made round directly due to gravitational action, if ya' don't believe me, please watch the source.

Answer 5

It is not round but Spherical. Sphere is the smallest shape in which maximum mass can be accommodated. This being done by gravity.Most objects in space whose diameter is more than 800kilometers are spherical.But small asteroids and comets are not!

Answer 6

Nature always takes the easiest way out. It tries to use the least energy. It cuts corners when it can. And the general shape of things is no exception. Circles and spheres are the most economical, energy-wise, to make things. They are the most compact shapes to be in. So, when there is enough matter to make a planet, it will have been made in a spherical shape. Same way with stars. Sure there can be deviations, like Earth being an oblate spheroid, Jupiter rotating so fast it's like a squished orange, etc. But the general tendancy in space is to be a sphere or be traveling in a circle. Nature would have it no other way.

Answer 7

The shape of small objects (like people and houses and mountains and small asteroids) are determined by their mechanical properties. You can take a rock and cut it into a particular shape and it will pretty much stay that way.

The larger the object, though, the stronger its gravitational field. Imagine that you want to build a really tall building. You have to make sure it has a really strong foundation, or the foundation will be crushed by the weight of the building and the building will fall. If there was anything really big sticking up on a planet or a star, gravity would pull it down.

If a planet was like a cube, the corners of the cube would be higher than the rest of the planet. Since planets and stars are so big, you cannot build a "foundation" strong enough to hold up those corners! Anything you built it out of would be too weak to hold them up. Gravity would eventually pull them down.

Even solid rock will flow like a liquid, although very slowly, if it is pulled by a very strong gravitational force for a very long time. Corners on a cubical planet or star would eventually just squish down.

Since gravity pulls toward the center of the planet or star, everything gets pulled down into a sphere. However, planets and stars are not really perfect spheres. They spin, so they bulge out a little around the equator.

Answer 8

The gravity of an celestial object like the moon and our earth attract equally on all parts of the body making it spherical, not exactly round.

Stars are not round or spherical in shape. they are actually jagged because they are clouds of gases and the continuous explosion of gases releasing heat and light makes it change shape all the time. when all the fuel (gas) is used up, the star eventually dies, but this takes millions of years to happen.

Answer 9

Since gravity pulls toward the center of the planet or star, everything gets pulled down into a sphere. However, planets and stars are not really perfect spheres. They spin, so they bulge out a little around the equator.