> Earth is the place to be. But it is also worth noting that even if we do end up colonizing space, Mars is still really pointless. Mars is not significantly more habitable than orbit

I’m not pitching a specific destination. And I’m not pitching exploration to the masses. Most people on the planet never have and never will leave their home country.

If we want to go to space, we probably want a lunar base.

> There’s some gravity: the wrong amount. In space, you can at least get 1G with centripetal force

Maybe this is important. Maybe it’s not. We need physiological experiments.

> In orbit, you are halfway to anywhere. On Mars, you’ve gone back down the well

In orbit you’re perpetually nowhere. On a surface you have in situ resources.

> Mars is just a bunch of irradiated rocks. Bring your own ecosystem, and wait a couple thousand years while it installs

Maybe it’s age. Maybe it’s moving from New York to Wyoming. Maybe those are the same thing. But I’m more of a red Mars advocate today than I was when I read Robinson’s trilogy in my twenties.

> only thing Mars has going for it is that it’s really far away, so we can still pretend to entertain sci-fi plans about colonizing it

It’s mass and an atmosphere. That’s a lot to what Earth has going for us.

> practical next step for space colonies would be large investments in additional space stations

Practical next steps are lots of experiments in centrifuges and micro and low gravity. To fund and focus that you need a goal.