why not??? I even believe that there 're more than one alien life on other planets!! the problem is: science haven't developed enough to discover those.
before Columbus discovered america. No one had known about it
I believe that there would be life forms on other planets. It only takes one cell to grow into a life form. They might only be insects of some description that has adapted to the environment; but I do believe there would be something out there. I wouldn't imagine that there would be intelligent life-forms though. But who knows?
I think, because we don't know the end of the universe, only that it is not finished, we can set it as unlimited big.
And in a unlimited big domain, I think that is not very possible that only one planet under unlimited ones has the ability to have living on it, like you said.
I believe that there are different alien life forms in other planets.
first, we must know what is life,
second,different life condtion result in different life forms.human still can't recognize all the virus the life forms on the earth, so now we can say nothing of the life forms on other planets ,which have so different life condition compare with earth.
third, all these just theory we must prove it .
Te knowledge we owned is not enough, but we are more and more close to the it, and it will be a long and hard time
I think it depends on your idea of life. I would find it nearly impossible to believe that there are civilizations out there. There doesn't seem to be any evidence of this. I do believe that there is life on other planents; but not as we understand it to be.