humans aren't about to colonize mars. At best we could put people on the surface for a week and return them home safely (with some non-zero probability of death).
What's really crazy is what it would take to build sustainable non-earth infrastructure if earth wasn't available. I mean, sure, start with space robots that can extrude aluminum, but ... if you read the story of the western colonizers, it was brutal especially if they couldn't get resupplied.