How come no asteroids or meteors never hit the earth?

if you look at far the gas giants moons some of them are almost all craters and even our moon is full of craters and aswell as mercury and venus and dont say its because of the atmosphere if hundreds of craters hit the moon all teh time then why dont some of them get through to erath and go throught he atmosphere and i think those meteors hit those planets at a time when the solar system was very active and hwo is it possible that they hit almost every rocky planet and moon dureing that active period but not earth?