Something Old and Something.... Actually it is all old.
Let define a new constant,
\({G}_{o}= {g}_{o}{r}^{2}_{e}\)
where \({g}_{o}\) is surface gravity and \({r}_{e}\) is the planet's radius and \({G}_{o}\) is ...well not a constant, not even for specific pairs of \( {g}_{o}\) and \({r}_{e}\).