The planet Mars has two moons, if one of them has a period 7 hours, 30 minutes and an orbital radius of 9.0 × 103 km. Find the mass of Mars.
\(\left\{\text{Given} \frac{4\pi^2}{G} = 6\times 10^{11} N^{-1} m^{-2} kg^2 \right\}\)
(1) 5.96 x 1019 kg
(2) 3.25 x 1021 kg
(3) 7.02 x 1025 kg
(4) 6.00 x 1023 kg