> it's easier to survive on mars for centuries than survive that fraction of a second of nuclear fire. I disagree. To the extent that you can stockpile supplie

> it's easier to survive on mars for centuries than survive that fraction of a second of nuclear fire. I disagree. To the extent that you can stockpile supplies to survive on mars through the nuclear event, moreso it is easier to stockpile supplies to survive in underground bunkers. > And it's not just nuclear - if you are going to have a single point of failure, it has to survive every possible thing - it needs to be nuke proof, germ proof, chemical proof, earthquake proof... Redundancy is much cheaper. I agree, and it's easier to design separate Earth shelters to withstand different catastrophe scenarios than elsewhere. > Presumably the martian back-ups would return to earth as soon as the danger of the calamity had passed, so you still get all the benefits of Earth's habitability afterwards. Only the pre-catastrophe society needs to build and support a mars base. Likewise for Earth-based shelters. And let's not forget that there are far more failure scenarios and it's harder to recover from them for a shelter based in Mars than for one on Earth.