The planet Mars has two moons, if one of them has a period 7 hours, 30 minutes and an orbital radius of $9.0 \times 10 ^ { 3 } \mathrm {~km}$. Find the mass of Mars.\\
\{Given $\frac { 4 \pi ^ { 2 } } { G } = 6 \times 10 ^ { 11 } \mathrm {~N} ^ { - 1 } \mathrm {~m} ^ { - 2 } \mathrm {~kg} ^ { 2 }$ \}\\
(1) $5.96 \times 10 ^ { 19 } \mathrm {~kg}$\\
(2) $3.25 \times 10 ^ { 21 } \mathrm {~kg}$\\
(3) $7.02 \times 10 ^ { 25 } \mathrm {~kg}$\\
(4) $6.00 \times 10 ^ { 23 } \mathrm {~kg}$