On the other hand, I quote from John 16:12:
"I have many more things to say to you, but you cannot bear them now."
The bible explains that there are many things we do not understand and know, and therefore there is room for debate on if there are aliens or other seemingly strange abnormalities in the universe. God's infinite knowledge leaves the bible scarcely enough room to fit it all, and most of that information which God does know... we are not ready to understand it. There are many things we can not comprehend, for we are not exactly capable of understanding somethings completely, like the universe itself. We know it is there, but we have a problem understanding the sheer vastness of it. God, however, being all powerful, has the ability to comprehend his own creations. What we find impossible would be like child's play to him.
In short, what I mean is that it is equally possible that there are aliens, on a biblical stance, because just because the bible does not list something does not make it so. Of course, there are equal arguments for both, although some of the debate itself stems from being close minded to the possiblity for some people.
Sorry if I interrupted your debate, I just felt my opinion could help.