On Monday, February 19, 2018 at 5:16:00 AM UTC-5, Ingo Siekmann wrote:   
      
   > >    
   >    
   > Could there be other evidence, like traces of "burnt" reaction mass?   
   >    
   > Bye   
   > Ingo   
      
   The solar wind blows out molecules very quickly.  Chemical rockets tend to use   
   reaction mass that is made of elements that are extremely common.  Nuclear   
   rockets (for instance salt water rocket or an Orion) would blow nuclear waste   
   around. The exhaust    
   from a spacecraft entering would have more than exit velocity.  Any traces   
   depositing on asteroids or moons would be individual ions.  You could look at   
   the ion composition of the interstellar cloud.     
      
   There should be signs of asteroid and moon mining.  If someone came and went   
   they would take fuel to go. You would have to date the mining activity.   
      
   A robotic mission could deliver the nukes.  In that case the robot is still   
   there.    
      
   Interviewing the survivors would be by far the easiest way to check.    
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)