[Z-man]

SoCal:
I have pondered this very thing quite a bit. Here is my reasoning that ties the two concepts together. Keep in mind that my assumptions here are based on my Judeo-Christian beliefs:

What if God created another set of Adam and Eve on a different planet across the universe? It is quite possible. Anyway, perhaps this Adam and Eve did not fall to the temptation of sin, but lived their lives in harmony with God. Now if these folks were without sin, that would imply that sin didn't slow them down in terms of development. IE: they would have the ability to develop superior technology, provided they've been around for about the same time we've been.

This implies that perhaps they do have the ability to travel great distances over the vast reaches of space. Which would explain why they can come here, and we can't go there.

One other thing - if they are sinless, perhaps God is preventing them from actually interacting with us - in order to keep sin from them.

Well, that's my theory.
-Z.