&gt; wouldn&#x27;t it still be easier to live here than on mars?<p>Maybe. What if it&#x27;s an artificial plague? What if any other number of catastrophic events cause the collapse of the civilization here?<p>Having multiple settlements elsewhere is insurance.<p>And, while Mars is one interesting place, there are other rocks we could easily settle and mine for resources. I don&#x27;t think Mars should be the first we tackle (I&#x27;d go for the Moon first) but I&#x27;m perfectly fine with humans spreading all over the solar system.