I believe in extraterrestrial life, and intelligent life elsewhere in the cosmos. I do not believe we will ever make meaningful contact with that life. It would be awesome, but the odds are astronomically against.
There's a slight chance that they are, but I seriously doubt it. Scientists HAVE discovered new worlds out there, similar to ours, with their own "suns" and "moons" which I find highly fascinating. LOL If aliens are real then when they get to earth they will be more far advanced then we ever were.
I don't "believe" in extraterrestrials. I don't "believe" in something when there's no evidence of it's existence. A better way to ask this question is to ask "Do you think there are extraterrestrials out there?", in which case yes, it's definitely possible that there could be other forms of life out there.