Mrrzy:

Actually, we've no idea what forms life can take, other than our own, and not even a comprehensive view of that. Extremophiles have only been studied for a few years, and we don't yet know what the limits of our own chemistry is, even before we start to think about other chenistries.

And don't let anyone tell you chemistry xxx is impossible- they mean they don't know how it could work. Creationists here are fond of quoting chemists who say our own life couldn't have started without a miracle, so even without disagreeing with them, how can they discount other miracles elsewhere?

I agree that you can do a calculation that says out of x stellar systems, x/n have planets, x/n/m have planets that create life, x/n/m/p have planets where life gets complex etc. etc., but there's many a mussel in a mickle, to adapt a Yorkshire saying, and the Universe is BIIIIIIIIIIIIIIG.

So they're probably out there, and it's probably virtually impossible that we'll ever meet or even know about them.