I was objecting to the comparison between mars and the american continent.  The value of the American for the Europeans was certainly higher than if it were completely desert.  Europeans brought countless species[1], and discovered large areas of fertile lands.<p>You are talking about current american economy that happened literally centuries later.<p>&gt; Economic value is primarily created by human activity.<p>Precisely.  If economic value depends on human activity and not on the location it takes place, then why spend hundreds of billions to do it somewhere else?  What exactly can you do on mars that you coud not do on Earth for much less money?<p>1. <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Columbian_Exchange" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Columbian_Exchange</a>