People need to start colonizing other planets

The argument

The argument for colonising other planets rests on a risk that cannot be managed from a single location. An extinction-level event — a large meteorite striking the Earth is the usual example — would end life on this planet, and no measure taken on the surface would alter that outcome once it occurred. If humanity exists in only one place, then any event capable of sterilising that place ends the species. Colonies elsewhere change the arithmetic entirely: the destruction of the Earth would remain a catastrophe, but humanity as a species would continue to exist in the settlements beyond it. For that to hold, the colonies must satisfy two conditions the argument sets out explicitly. They must be numerically large enough to avoid dying out on their own through a low birth rate, since a settlement too small to sustain itself merely postpones the extinction it was built to prevent. And they must be independent of the Earth for supplies, because a colony dependent on resupply from home is not a refuge from the loss of home — it fails as soon as the shipments stop. Two routes to such settlements are identified. One is terraforming: altering a planet's atmosphere and soil to make it resemble Earth closely enough to support people directly. The other is building artificial habitats designed to sustain themselves by exploiting the resources of the planet they sit on, without waiting for the planet itself to be transformed. Proponents accept that either goal is remote. Their conclusion is that remoteness is a reason to begin rather than to defer, since the initial effort is what makes eventually reaching it possible. Because people need to start colonising other planets, manned space flights are worth it.

Premises

Counter-arguments

Most of the planet in the solar systems are not habitable. Terra-forming is not a viable option since it would take centuries if not more. Self-containing habitat might be unable to be self-sustainable and a minor issue could put colony survival in jeopardy

Rejecting the premises

Technology can not allow a self-sustaining environment nor terra'forming

Framing

There is a push to continue space exploration. Human colonies are the logical step forward in this process.