c program to take density and mass and spit out radius
          print*,'Enter mass in kg, and density:'
          read*,w,rho
          volume= w/rho
          print*,'This has: ',w/1.899e27,' Mj'
          print*,'  '
          radius=(volume*3.0/4.0/3.13)**0.3333
          print*,'Radius =',radius,' Rj = ',radius/6.99e7
         stop
          end