Science Buddies: "Ask an Expert"

Hello,

I am not a person who has deep knowledge on Space sciences, I am a Metallurgist, but I have a question in my mind which is to be clarified in the area of Astronomy.
We all believe that the Earth and other planets are evolved after Big bang.

Question:

1. After big bang, what made all the planets and stars look almost spherical in shape ?
2. Have scientists found any planets or stars which are irregular (e.g: trigonal, hexagonal etc.) ?

Thanking you

Hi Kandalam,

Are these questions related to a K-12 science fair project? If so, what is the question you are trying to answer or hypothesis you are trying to test? If these questions are not related to a science fair project, then a different set of online forums would be a better way to get your questions answered.

That said, stars and planets are spherical because (1) the force of gravity in these objects is stronger than the strength of rocks, metals, and ices (in the case of planets) and hydrogen (in the case of stars) and (2) a sphere is a low-energy arrangement of matter that facilitates hydrostatic equilibrium. No stars or planets are trigonal or hexagonal, that we know if, and it's highly unlikely that we will find something like that. Many stars and planets are slightly "flat" due to their rotation (they are "oblate spheroids" instead of perfect spheres).

Thank you for the great post. It was really useful for us.