I’ve long thought that Mars was a natural target for Mankind to diversify our location and to create a species that can’t be wiped out by one tragedy. I always thought, “Moon, then Mars.”
I’m not so sure anymore.
With the discovery of lava tubes on the Moon, it is improving on the chart. I think it’s looking like a good choice more than ever, mainly because it seems to be providing natural shelter for colonies below the surface. There is water, there is abundant solar energy, and there is shelter from cosmic radiation and huge heat variations over the night/day cycle. It’s close to home and emergencies don’t necessarily mean help can’t be provided from Earth.
Titan is rapidly becoming my 2nd choice. The atmosphere is very close to that of Earth in regards to pressure. So no pressure suit required to be on the surface, just a source of heat and oxygen. There is ice, there is methane. Energy from hydrocarbon fuel sources is virtually unlimited there. Solar is not going to be practical, but the moon itself is one giant energy source. Combustion engines and generators are a natural fit for Titan. Because the pressure is close to Earth, construction doesn’t need to be as robust. Saturn isn’t a high radiation environment to the degree that Jupiter is. And there are lots of other moons in the Saturn system to provide metals and volatiles as needed.
Plus Titan may be way more interesting than we expect. If nothing else, it’s a natural port for the outer solar system.