What do humans need?

[Dartz]

There are many assumptions about life on other planets. Most scientists agree that the planet must meet the following conditions: stable orbit in the habitable zone, geologic activity, a stable weather pattern, and the right mass.

Now, if you are looking for a planet for humans to colonize, would the requirements be as rigid? To what extremes would the technology we currently posses, or in the process of developing, allow us to survive? How stable does the planet's orbit or tilt have to be? How small, or massive, can we handle? What conditions would be too much for us?

[vh]

Depends on how far in the future. As technology gets more advanced, it'll be easier and easier to convert any planet so that it is suitable for human life. Also it depends on how much money we are willing to spend. Terraforming mars might be possible, even, but it would require enormous amounts of resources currently.

[blotz]

inb4 every planet has a colonize button.

[Daryl95]

Major issue: Amino acids. If the chirality is opposite of ours then there'll be no use eating anything. We'd have to import food, but perhaps that is preferable to disease.
Chirality - mirror image of a polar molecule
  C           O  O
 / \            \  /
O  O           C

Kind of like this only a little more complex.

Of course it is possible that disease won't factor as much either way as many times on Earth virulent lifeforms can infect only certain species and must adapt to humans.  So as long as we don't start throwing our feces in the river again (Black Plague) we may be fine.

Also assuming God wasn't a human in which case disease would more easily spread.

The planet won't likely be like Star Wars where most of the surface is just one climate. There will be a variety and people of different geologic regions on Earth may flock to different climates on the planet. But as for differing environments humans adapt to different environments all over Earth.

May think of more factors later.

[vh]

Could you just grow food instead of importing it constantly?

[Daryl95]

Plants grow on Earth in a system that recycles the dead put nutrients back into the soil. I don't know that growing plants wouldn't be an issue if you're growing them out of an opposite chirality system. You might grow them on an orbital station with Earth soil.
Then if it's not an issue, there is still climate and the matter of crowding the ecosystem of the planet with extraterrestrial imports that shouldn't be there.

Another issue is whether or not the difference in the parent star's rays would hurt humans.

The gravity and atmospheric pressure could be another two issues.
Humans may get used to different pressures as it ranges at different altitudes on Earth. (.75 - 1.5 atm) As for gravity, we'd get used to lower Gs but higher ones may be a problem. Habitable exoplanets probably range from 1-3 Gs as most known are super Earths.