Where did you get the number? Our solar system alone formed 5 billion years ago (i.e. 9 Gy after the big bang). The milky way is thought to have formed somethin

Where did you get the number? Our solar system alone formed 5 billion years ago (i.e. 9 Gy after the big bang). The milky way is thought to have formed something like 1 Gy after the big bang.