Nope. We can't and sadly this kinda disproves religion too.
It can also be argued though, that man's idea of a "god" is actually just a higher life-form, come to earth to do something. Aztec's Quizicolta and our God may be the same being. We could all just be a science experiment.
The thought that prayer saved/helps can be tied to human's innate psychic abilities. We all have them, on some level, some higher than most. A group of people praying for one thing to happen pools a lot of energy, and i believe in fact does make it more likely to happen.
In a way, i'd be disappointed if that were the case. It does stand a chance of being true though. I guess we won't know though until something happens to make us aware of them. Meh.
I would be ecstatic to learn of any life, be it intelligent or simple, outside of our solar system. You can't tell me that finding the alien equivalent of a dog wouldn't be ****ing awesome. Don't get me wrong, I've always wanted to learn of beings more intelligent than humans, but I wouldn't be disappoint if all we found was a webbed Fido swimming under the crust of Europa.
WAT?