I have long been skeptical about the prospects for off-world human colonies. Given that the International Space Station is the most expensive thing we have ever built and it is entirely reliant on supplies from Earth, it would be a gigantic leap just to make a self-sustaining closed life support system. Beyond that are many other obstacles, from radiation to Mars’ reduced gravity and even interpersonal conflict.
George Dvorsky has written an article with details on many of these challenges, which also quotes Louis Friedman on the psychological and philosophical implications of extraterrestrial expansion as an unlikely prospect:
If humans can’t make it to Mars, it means we’re destined to be “a single-planet species,” he said. What’s more, it suggests extraterrestrial civilizations might be in the same boat, and that the potential for “intelligent life to spread throughout the universe is very, very gloomy,” he told Gizmodo.
“If we can’t make it to a nearby planet with an atmosphere, water, and a stable surface—which in principle suggests we could do it—then certainly we’re not going to make it much beyond that,” said Friedman. “But if we’re doomed to be a single-planet species, then we need to recognize both psychologically and technologically that we’re going to have live within the limits of Earth.”
There’s a case to the made that the principal role that Mars is now playing for humanity is as some kind of faint hope that we can wreck the Earth and still somehow survive. That’s probably not healthy on any level. Having a crazy, desperate backup plan isn’t a substitute for a credible plan that doesn’t disregard or sacrifice almost everything humanity has ever valued. Furthermore, to degrade the Earth to the point where it no longer supports people would be an act of vandalism and malice toward the rest of life so severe that it would raise grave questions about whether it would be good for any life form, including us, for people to continue to survive.