From: wthyde1953@gmail.com   
      
   Bobbie Sellers wrote:   
   >   
   >   
   > On 2/20/26 13:53, William Hyde wrote:   
   >> 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   
   >   
   >      If we get to the point of moving asteroids and the like odds and   
   > ends we   
   > might be able to get enough dense elements into Mars to give it decent core   
   > then water and Oxygen would not leave so fast.   
      
   Alas, the mass of the entire asteroid belt is not enough to   
   significantly increase the mass of Mars.  Not even adding Mercury, Pluto   
   and all the system's large moons would matter.   
      
   We'd need to add Venus to Mars to get a decent mass, and of course if we   
   could move Venus out that far we wouldn't need Mars.   
      
      
      Moving Mars inward would   
   > take a lot more energy than we can consider presently.   
      
   Everything is more than we can do presently.  But not more than we can   
   consider.   
      
   But if we just wait 500 million years the sun will be five percent   
   brighter and it's larger atmosphere will emit less UV, thus making it   
   easier for Mars to hold onto gases.  Which will be very useful as,   
   unless it's been moved, Earth will be uninhabitable by then.   
      
   William Hyde   
      
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