Asteroid Gravitational Interaction - What's Going to Happen in the Future?

When an asteroid gets really close to the earth, it is gravitationally affected. This creates all sorts of uncertainties in the future orbit of the asteroid. Century one could not calculate that if an asteroid was going to comeReally close to the Earth. Now century two can do that with high confidence. And so i feel a little safer now. But i won't be happy until we have that deflective beam obelisk from that classic ttric episode.