That’s not even remotely comparable. North America etc. turned out to be effectively more “habitable” than the old world due the abundance of fertile land and o

That’s not even remotely comparable. North America etc. turned out to be effectively more “habitable” than the old world due the abundance of fertile land and other resources relative to population. That can never happen on Mars. > Human history is full of people who have done exactly this. Are there any self-sustainable colonies in Antarctica (which is more habitable than Mars by at least several magnitudes)? So not humans have never done anything even remotely close to what colonizing Mars would require.