Originally Posted by ModernPuritan?

3,00,000,000,000,000,000,000,000,000,000 years ago, a big explosion occured sendint out the right amount of particles, the right mixture at the right speed into the right direction in space. at which point they collided with other existing fragments at the right speed with the right composition to set off a reaction that took the right amount of itme to prodeuce stars. that is how they got there

or you could except a more logical and simple answer and turn to Genesis 1.