Mars: The New Frontier
Living on the surface of big balls of rock is just such a waste of mass.
It is so much more efficient, and so much safer, to live on the inside of a spinning cylinder encased in a radiation shield. Mars doesn’t have an active magnetic pole, so radiation is a problem.
So much easier and safer to develop self replicating robotics that can then assemble large habitats for us in orbit. Taking about 1,000ft of rock off the far side of the moon would give us enough mass to give an effective surface area equal to that of the earth, in local orbit (about 10,000 habitats for a million).
Once we get all the bugs out of those systems, then we can build travelling versions, with a million or so people per habitat. At one tenth G acceleration it takes 10 years to get to relativistic speeds, so about 30 years ship time to anywhere in the galaxy. That tech should be stable by the end of this century.
The power of exponential development is so much greater than anything linear.