From: nedlatham@woden.valhalla.oz   
      
   Sylvia Else wrote:   
   > Luigi Fortunati wrote:   
      
   ----snip----   
      
   > > Earth A telescopes detect meteorite P approaching, make their   
   > > observations and see it in the vicinity of a distant 156-year-light   
   > > star.   
   > >   
   > > So they do not worry because they know they have more than a century   
   > > and a half to set up some defense of the Earth from the devastating   
   > > impact of the asteroid P.   
   > >   
   > > But the asteroid is only 5 year-light distant and in just over 5 years   
   > > it destroys us all!   
      
   It's travelling straight at us at 0.97 c?   
      
   Get real.   
      
   > > This is because we do not see the asteroid approaching in the point   
   > > where it is "now" but we see it in the point where its image (which we   
   > > receive now) had started in its time.   
   >   
   > I rather doubt that astronomers and scientists in this situation would   
   > make such a mistake. In any case, the apparent distance to the object   
   > divided by its apparent speed towards us, gives the correct time for it   
   > to arrive.   
   >   
   > Whether we could expect to do anything about such an object is another   
   > matter.   
      
   Indeed. A rendezvous might be a tad difficult.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)