where did all the matter in space that makes up the stars and everything come from??

[Austin D]

like scientist believe that dust in space collected together and thats what formed our solar system and all the planets and stars and galaxies in the universe so where did that dust come from that formed all of this? it had to have come form somewhere

[Michael Steen]

You have to do some extensive reading on the Big Bang theory. It's incredibly complicated and too deep to go into here (as if I could anyway!!), but it has to do with the conversion of energy into matter.
Einstein's theory of E=mc2 suggests that matter and energy cannot be created or destroyed, but one can become the other.
At the moment of the Big Bang there was no matter as such, but it coalesced out of the energy state as the universe cooled.
Yeah, I know it sounds bizarre, and I don't have the physics or the math skills to demonstrate it, but it seems to be what the big guys have come up with so far.