Paladin426 said:
I would say that alien microbial life is definetly possible. That fact that we are here is by complete chance with how far the planet is from the sun, but I would say that there is a good chance that life exists elsewhere.
I'm pretty sure the consensus amongst astrophysicists is that microbial life at the least is certain, no longer just probable

.
In fact once they get a manned mission to (I believe) Titan they are expecting to find something akin to fish beneath the ice.
There is absolutely no reason to assume that humans are it.
There are organisms that do not require water and eat nothing but stone, that means that any source of stone in the entire galaxy could potentially harbor (albeit small) life. Life as we know it is difficult to find on other planets. Mainly because life on other planets won't be life as we know it.
But I can promise anyone in their 20's that plans to live into their 80's that we'll (assuming we don't all succumb to bacteria or war) find life on another planet in our own solar system.
If we are lucky it'll be those spider-man symbiots (one can dream...course I'm being silly at this point).