paragraph: Gravity is a force, but not like other forces you may know. Gravity is a bit special. You know that a force is a push or pull. If you push a ball, it starts to roll. If you lift a book, it moves upward. Now, imagine you drop a ball. It falls to the ground. Can you see the force pulling it down? That is what makes gravity really cool. It is invisible. Invisible means you cannot see it. But wait, it has even more surprises. Gravity holds planets in place around the Sun. Gravity keeps the Moon from flying off into space. Gravity exerts a force on objects that are not even touching. In fact, gravity can act over very large distances. However, the force does get weaker the farther apart the objects are. 
question: What is gravity's role in space?
answer: Rotates planets