> This is the insurmountable problem with human habitation of Mars - we would need to become, in many ways, a different species in order to withstand the very g

> This is the insurmountable problem with human habitation of Mars - we would need to become, in many ways, a different species in order to withstand the very greatly reduced gravity - and humans, as we know them, would succumb to all manner of disease and physical maladies until that transition (millenia ?) took place. Well, you don’t know that humans can’t survive indefinitely at 1/3 gee. I know that because no one knows that, so let’s not speculate on what the threshold gravity would be before we need to “become a different species” would be. But I’ll admit, unlike radiation and resource concerns, gravity is something we’re never going to overcome. If humans can’t thrive at 1/3 gee, we will never permanently colonize any terrestrial body in our solar system. However, given the range of adaptations humans present, e.g. to extreme altitude, continuous saltwater diving, or long-distance running, I’m willing to bet we can handle, and adapt to, reduced (not micro) gravity.