$${\begin{align}E &= -\frac{GMm}{2r} \\& = \mathrm{\frac{(6,67 \times 10^{-11}\, N \cdot m^2/kg^2)(5,89 \times 10^{24}\, kg)(7,20\, kg)}{(2)(6,27 \times 10^6\, m)}} \\&= -2,14 \times 10^{8}\, \mathrm{J} = \underline{-214\, \mathrm{MJ}}\end{align}}$$