It is almost impossible that a universe this huge is not teeming with life. However, the distances are SO great, reaching each other may well be impossible with the limitation of physics. I don't know if any civilization will send off members to travel, millions of years, and multi-generationally to find another civilization, only to lose contact with their own!!!

National Geographic had a little fold out a year ago, showing where we were, in scale, to other planets in the area. The distances were SO vast. I don't think the human mind can even grasp it.

Those WERE "aliens". They were nurses from Malaysia and the Philippines. (seriously....I hope you are OKAY after that accident).

If I were able to reach other planets, and found one that had intelligent life on it, my first thought would be, "Hey, this could be a good learning experience!" or, "Perhaps we could be friends" (or more accurately, "DUDE! I could be buddies with ALIENS!!!" )

I don't think hostile reasons are the only ones to branch out, explore, and meet new people. Not to say your fears are invalid, just giving another perspective.

Interesting to note, though, that while we have yet to definitively identify any other celestial bodies with life, there's at least one possible candidate right here in our own solar system - not a planet, but Europa, one of the moons of Jupiter. It's considered to be one of the candidates for habitability in our system, and there's a possibility that, under its ice-ocean, there may be life similar to that which is found near deep-sea thermal vents right here on Earth. Almost certainly not intelligent life, but perhaps something more impressive than bacteria.

Obviously, possibility and reality aren't always the same thing. Until we can actually explore Europa in detail, we won't know for sure. I would love to still be around if and when we do find out, though!