The energy involved in "crashing" whether it actually killed the few remaining dinosaurs is so high that no known material or theoretical energy force could have allowed living things to survive - so dead aliens. Besides, our genetics fits in with almost all the other small species on the planet.
IF (a very big if) a meteorite actually killed off the dinosaurs, then it must have been such a big (and fast) "UFO" that nothing would be left of it. It would have been vaporized, with any molecules present on it, reduced to elements. This would make it impossible for anything to have developed from any molecules on the "UFO", since ZERO molecules would have survived.
PLUS: it is clear that all DNA on Earth (ours, mammals, reptilians, birds, fish, etc.) evolved from the RNA of plants that were already present on Earth, hundreds of millions of years BEFORE the "meteorite" finally hit.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.