funny thing is that you spelt astronomy right... even though you tagged your own dodgy spelling but then proceded to spell homework wrong! (lol)
that's an awesome question though... and I often wonder the same thing...
science says...
In the begining there was nothing, no universe, not empty space of vacume... just nothing, then the big bang happened...
but if there was nothing what was the big bang caused by? a couple of nothings bumping into each other?
the night sky is black because there isn't enough light there... but what colour was nothing?
E=mc^2 suggests that if there was plenty of energy then some mass could be made... but the universe has a hell of a lot of mass... if there was nothing... then where did this all come from
ever think that it was easier when everyone just believed that some divine power made everything?