are all planets and suns the same shape ?

[icebread]

and if so, why?

[Andyvon]

Basically all stars and planets are spherical due to gravity acting equally on their surfaces. Smaller objects such as asteroids and small moons can be irregular shapes if they are too small for gravity to form them into spheres.

To confuse things, many stars and planets are not perfect spheres as their circumferences are slightly wider when measured around their equators than around their poles. Those shapes I believe are termed 'oblate spheroids' and they form as a result of centrifugal forces bulging the body as it rotates. Anorak or what?!

[factor-fiction]

I seem to remember from school that the earth isn't quite a perfect sphere

[sddsddean]

As Andy says, the Earth is an oblate spheroid.

[heathfield]

Some stars are egg-shaped! In a binary system, where two stars are rotating around each other, the gravitational forces can distort their shape into an ovoid, with the narrow end pointing towards the other star. Where one star is less dense that the other, matter can even be drawn from it toward the more dense star, where it is either absorbed, or else produces a Saturn-like ring. This can give the less dense star a shape like that of an onion!

http://en.wikipedia.o...isk_Binary_System.jpg

[waterbabe]

They are all round because they are spinning so fast the corners have blown off

[icebread]

Thank you all for your answers,and your time