What if the asteroid that crashed into the earth 65 million years ago was an alien spaceship, and we are the aliens?
As I am in the UK , as far as I am concerned you are an alien . I suppise that works both ways !
In a roundabout sense, that is highly likely. The genetic makeup, to create beings like ourselves, wasn't here beforehand. So, the probability would seem high. At best, we're an act of random chaos. In the debate of "why we are here." Realizing the construct of the universe is infinite. Then so are the possibilities of how our existence came to be. If I had to answer "Why we're here?" I would say, the opportunity of being human is just that. Be a human. Be as random as our creation, as fragile as our bodies, as capable as our energy will allow, as human as humanity will afford. Individually we are temporary. Yet our origin and legacy are infinite.
Pardon my rambling. Just my two cents.