Not as a certainty, no. Given that kind of time frame and a very far object, neither our measurements, nor our calculations could possibly be precise enough to

Not as a certainty, no. Given that kind of time frame and a very far object, neither our measurements, nor our calculations could possibly be precise enough to know anything other than a probability of an earth impact. Unless we are talking about a big object hanging out nearby, slowly getting closer, in which case I have plenty of non-scientist acquaintances who will be pointing telescopes at it and verifying.