Suppose, just suppose, that mankind decided to move to a planet or moon further away from the sun yet still within the solar system. Initially, we would focus on a where and then a how. On the other hand by focusing on a where, we may be precluding other where's, other how's, and other when's.
Maybe the big issue is why!
Human beings will accept a path when someone already goes down that path. The reason is that we are programmed to be copycats. If I say hi to you as I approach you, the chances are that you will say hi in return. Sometimes, you will and sometimes you won't, but being a human being the chances are that you and most of your friends mostly will. Try the experiment yourself.
Suppose that one of the pyramid projects such as the fusion reactor suddenly appears on earth as a usable energy source. Earthlings will build such reactors and make them smaller and smaller until they easily fit into a space ship, yet powerful enough to travel to a distant habitable moon within the solar system. Perhaps, we will have a hybrid technology such as a solar sail that with plasma thrusters and plasma engines that can easily carry us to distant moons.
By the time of our future migration from earth, our desire to have so many children will be considerably reduced because we will live longer. We will arrive at the distant moon and be so cut off from earth that we forget who we are. The elders who live to be 800 plus years old will write down what they have experienced and the rules they were told by the distant boss on earth. They will create a teaching to live by and a collection of writings to show their children how to survive. It probably won't be called a Bible, but the fact that it could exist might make one think?
http://bigthink.com/ideas/21570
Will ye no think kindly on those who would be your friends! May the sun shine with your thoughts, today, and happiness grow in your heart! May you allow yourself some peace of mind.