re: #1 Achilles Tang

What occurs to me is that this could make Mars more habitable. It would provide some atmosphere and heat and shock waves that would likely melt great amounts of subsurface ice, and maybe start some new volcanoes putting more gas in the atmosphere. That would be something to see.

Mars still has no magnetosphere so any atmosphere created would be blown away by solar wind over time. Any terraforming process used on Mars will have to be an ongoing process, even after colonization, unless we can create an artificial magnetic field or restart the spinning of Mars’ core.