Originally Posted by masaki
Well I think it is very possible that a huge explosion for whatever reason could blow a huge ball of rock into pieces that slowly became planets or something. But I don't know how planets are round. Did they erode(sp?)
About the Big Bang theory: http://en.wikipedia.org/wiki/Big_bang
About the forming of stars: http://en.wikipedia.org/wiki/Star
About planets: http://en.wikipedia.org/wiki/Planet
Most important quote:
Planets are thought to form from the collapsing nebula that a planet's star formed out of, aggregating from gas and dust that orbits the protostar in a dense protostellar disk before the star's core ignites and its solar wind blows the remaining material away.
Oh, and planets are round due to gravity.
You could also look at:
I think this site reads a bit easier than the other ones.