I'm sure it's a dumb question, but it's a genuine one. How do we know that the Yucatan crater is from an asteroid, and not from some kind of man-made explosion created by an advanced civilization?
Basically: because it has a lot of characteristics in common with all the other, better preserved, asteroid craters we know of. So our hypothetical advanced civilization would have to have deliberately mimicked all the little details of an asteroid impact, not just created a big explosion using some other method. That's possible, of course, and if they did it well enough we'd never know. But it seems much more plausible that it was an asteroid impact.
Maybe they had started asteroid minding and in an attempt to bring one into local orbit, it went horribly wrong.
Bomb explosions look fundamentally different from meteorites. Both may be modeled by modern tech.