I took an Astronomy course the fall of my Sophomore year at college.
Why? Because there was an unbelievably hot girl there who's butt I wanted to sit behind and stare at. I was 19. What else concerns a 19 year old guy?
At any rate, it was one of the best classes I ever took. One of the homework questions accompanying the final chapter was something like:
"There are (very roughly) 10 to the 11th power Galaxies that exist to our knowledge; and there are (very roughly and conservatively) 10 to the 11th power solar bodies that inhabit each one of these Galaxies. Given that 0.0000001% of them have the correct conditions to sustain life, what are the odds that there is intelligent life out there in the universe?"
The odds are exceedingly high that there are other beings out there, and exceedingly, exceedingly low that we are the only ones out there.
The questions can only be: Who, What are their intentions, What can we learn from their technology, Can we communicate, and have they visited us in some way, shape, or form.
Hate to sound like a nut, but all these UFO/Alien nuts/Military people can't be wrong.