Mass of asteroid          M   =  3 x 10^9  kg

   Mass of ship              m   =  1 x 10^4  kg

   distance between          d   =  150       kg

   Gravitational constant    G   =  6.67 x 10^(-11)    N*m^2/kg^2



      Q:  What is the size of the gravitational force on the asteroid?


                        G * M * m 
               F   =  --------------
                          d^2


                       (6.67 x 10^(-11)) * (3 x 10^9) * (1 x 10^4)
                   =  ---------------------------------------------
                                      (150)^2


                   =  0.09  N