i saw several shows that said that too. also eventually the moon will slow earths rotation so that the earth will be tidally locked to the moon. and in a long time (billions of years?) the earth will rotate more slowly than the moon and tidal forces will cause the moon to fall into the earth, make an extremely close pass and be flung out of earths gravity, or almost hit the earth and break up into a ring of particles around the earth. if i had to choose one of the three to happen i would choose the third it would be awesome if earth had its own rings.