Recently there has been a bit of activity in news and media regarding the likelihood of Earth-size (correct gravity) planets in habitable zones (correct temperature) of their home star [see one here]. This means that the planet could potentially host human life.
When considering that possibility I begin thinking about what would happen to the state of global society if those options were to be explored and colonies were to be established. At present the estimates are that the closest planet would be 13 light years away. We do not yet have propulsion methods that will allow us to make the trip in a human lifespan. Crafts that were launch in the 1970s recently left the solar system, which is only about 25 light hours in width. Assuming we could establish faster methods, Einstein’s theories tell us that in the context of this dimension of the universe we can not exceed the speed of light. So at a minimum it would be a 13 year trip to the destination, using normal space. Even if we were to utilize some theoretical propulsion mechanisms, it does not resolve the problem that all existing communication mechanisms function at about the speed of light. As a result of this delay, any such colony would be essentially cut off from Earth and would experience a separate cultural evolution.
The current state of global culture is one that is very connected. People develop very complex social networks that span large geographic spaces. The current state of technology makes this possible and has created a social structure where no one ever has to really let go of people who were at one point geographically close to them if they move. To embark on a colonizing mission to another planet, no matter how close it may be by astronomical standards, reverts the social connectedness of the colony to a state that may resemble something from 1492. The colony would be small, insular and removed from its source culture.
Perhaps there are people who would enjoy such an opportunity, but for me it seems like something that would be very difficult and would potentially require quite a bit of preparation.