I've always thought there were aliens out there somewhere. As we slowly fill in the numbers in the Drake equation, it becomes statistically ever more likely. Why they'd come to a backwater part of the galaxy liek Earth is another matter entirely....

Of course, we don't know how advanced they are, but if they are able to come here they'll have to be more advanced than us. Either in terms of FTL travel, stasis technology or super-extended life expectancy.

If we want to know how that goes, we only have to look at what happened in the Americas (North, Central or South, the results were pretty much the same) when the Europeans turned up.