The asteroid would have to be unfeasibly massive for its gravity to have any detectable effect on the Earth, or indeed the Moon. We are 'grazed' by asteroids known as Near Earth Objects (NEOs) on a relatively regular basis, but unless you keep up with astronomical bulletins, or happen to pay attention to the night sky, you'd never know.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'