Earlier quoted context omitted.
Mars has way more sunlight (much closer to the sun and a much thinner atmosphere), which makes solar much easier. So equipment, supplies, and solar could be on the surface, and the radiation sensitive humans could be a few meters underground. As you mine for water you could dump the useless stuff on the surface and use the emptied space for living quarters. Question is why live somewhere that's tougher than the top o…
But if you're only doing it to safeguard against extinction level events why not just set up multiple contingency populations underground here on this planet? They won't have to travel as far after the event.
If an ELE hits, few would be around to make even that short trip to the bunker.