I don't think Homo Sapiens will ever colonize anywhere else. We may send out DNA, but certainly not whole people.

Humans are the product of millions upon millions of years of interaction with the surface environment with Earth. We are a robust species as long as we have what Ma Nature provides and extremely fragile otherwise.

In order to colonize we'd have to recreate and maintain an environment resembling Earth's in a hostile area. We'd need to be able to manufacture spare parts, smelt metals, create plastics, make fabrics, antibiotics, glues, food, water, oxygen, maintain atmospheric pressure, protect from radiation.

And then there are the personal issues. How well would humans do living in that environment without hope of anything else? Trapped in a small area with only the creations of bygone ancestors for entertainment, and those depicting a rich, diverse world, knowing that life holds no opportunities outside of that colony. Ever. Look at how the Biosphere kind of things turn out.

I think the wishful thinking about colonization keeps us from doing what we have to to survive here. After all, we are doing our best to make this place uninhabitable, what makes us think we could make someplace else fit to live on? If we can't take care of here, starting by limiting our population, we don't deserve another shot.

We've been given one Earth. As She goes, so goes we. And I don't think humans have the pshychological restraint to make it work for much longer.

Arf