From: andreww@headfirst.co.uk   
      
   Marc 182 wrote:   
      
   >Most of the power decrease is caused by the degradation of the thermal   
   >couples in the radiation environment.  Plutonium 239 has a half life of   
   >over 24 thousand years, fast in geologic time, but infinite in human   
   >engineering terms.   
      
   Plutonium RTGs use plutonium 238, which has a half-life of 87.8 years.   
      
   Andrew   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)