The Force That Holds Us

Have you ever wondered why a ball always falls back to the ground instead of floating away? The answer is gravity, an invisible force that pulls objects toward each other. The bigger an object is, the stronger its gravity. Because Earth is so large, its gravity keeps our feet on the ground and holds the air we breathe close to the surface. Gravity works across huge distances too. The Sun's powerful gravity pulls on all the planets and keeps them moving in wide circles called orbits. Without this force, the planets would fly off into space, and life as we know it could not exist.