From: wthyde1953@gmail.com   
      
   Tony Nance wrote:   
   >   
   > An article I just ran across   
   > https://bigthink.com/books/science-fiction-mars/   
   >   
   > Titled   
   > "Science fiction blinded us to the perils of settling Mars"   
   >   
   > With an immediate by-line of:   
   > "Science fiction romanticized Mars as a place of adventure and future   
   > settlement; science tells a very different story."   
   >   
   > In which the author and his main source tell us that Science Fiction has   
   > Mars all wrong.   
   >   
   Wow, talk about low hanging fruit.  But I suspect his rent was due.   
      
   Even  the children's science books I read many decades ago made it clear   
   that 99% of the science fiction versions of Mars were far too optimistic.   
      
   And even those books erred on the side of habitability.  There was some   
   emphasis on the fact that equatorial temperatures could reach 80F, and   
   the atmospheric pressure given was well above the actual value.  The   
   poisonous soil was of course not known.   
      
   In 1990 a writer in the British Interplanetary Society journal estimated   
   that a decent atmosphere and hydrosphere could be produced with ten   
   thousand properly placed 10mt bombs.  I'm not entirely sure any longer   
   what he meant by decent.  A fifth of an atmosphere, at a guess.   
      
   If this is so, the atmosphere would indeed leak away into space, but on   
   a timescale that is very slow compared to the human one.  It would not   
   be necessary, as the article implies, to continue to bombard the planet   
   with nuclear weapons.  The atmosphere could be maintained with less   
   drastic but still enormously expensive means.  Which opens the way for a   
   Leigh Brackett story about people dwelling on a cooling and drying   
   post-technological Mars...   
      
   But getting the temperature up to the point that liquid water won't all   
   condense in ice caps is also a difficult problem. The CO2 levels   
   required are very toxic.  We need a molecule which is strongly absorbing   
   in the IR, chemically neutral, and which does not disassociate into   
   something damaging in the upper atmosphere when struck by UV radiation.   
      
   A gigatonne or so of that in the atmosphere, and all we have to worry   
   about is radioactive waste from the bombardment and  the poisonous soil.   
      
   All in all it would be easier to move Mars closer to the sun.  Then deal   
   with the soil.  Might not be possible for a little while.   
      
   William Hyde   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)