Originally Posted by Redsfaithful
I don't think people who believe in aliens visiting have any real idea just how huge space really is. It's so unlikely the chances are basically zero.
But they're not traveling through space, they're traveling through time. They're evolved humans from the future. That's why they look basically like us (two arms, two legs, etc). Their craniums are bigger, that follows the evolutionary pattern.
Besides, all you'd need is a wormhole, which shouldn't be that hard given that the timeframes involved are of the same scale as the distances. What will human technology look like in a million years, given what we've accomplished in the last 200? A million years is blink of an eye on a cosmic scale. An alien civilization might have a several billion year head start on us.