I have to agree with what several others have said: I believe that there is life on other planets, that the same God we worship created that life. There is nothing in Genesis that contradicts this. No where does is say that this is the ONLY planet God created. It says that God created EVERYTHING, all planets, all life, then it goes on to talk about what God created on this particular planet. The Bible doesn't talk about what God created on other planets because (a) it doesn't concern us, and (b) the writers/recorders of God's word would have no knowledge or ability to transcribe what God was saying if God even wanted to talk about it. I mean, sure, God wrote the Bible, but he was limited by the human language available at the time the Bible was written. That's why the sun is not described as a star, the sky is described as a dome (rather than the great expanse that it is), etc. It's all based on what humans could conceive at the time. God could only get ideas into the heads of the people that they're heads could comprehend.
As for alien encounters, I also agree with what most people here seem to be saying: I remain suspicious. I don't want to say "never." I like to keep an open mind. I would say the likelihood is high that what most people experience as an "alien encounter" is some combination of imagination and/or supernatural phenomena (i.e. demonic, angelic, or just plain other-worldly, as in from the spiritual world, not extra-terrestrial). That is not to say that we will never encounter life from other planets. Like I said, open mind. You never know. But has it happened? I doubt it. As huge as the universe is, and as rare as it is for life to happen, I think there are many millions of light years between life-sustaining planets, so it would be eons before any beings had the ability to travel that far. But it sure is fun to fantasize about. Love the movies books and tv shows!