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The Kepler-20 system has planets with masses in the following order, going outwards from the star: Kepler 20b: $\approx 10 M_\oplus$ Kepler 20e: $\approx M_\oplus$ Kepler 20c: $\approx 16 M_\oplus$ Kepler 20f: $\approx 1.5 M_\oplus$ Kepler 20g: $\approx 20 M_\oplus$ Kepler 20d: $< 20 M_\oplus$ If Wikipedia is to be believed, Kepler 20b may be a ...
No. There are two simple arguments, each on its own alone enought to refute such thought: First way: Tidal force is the gradient of the gravitational attraction. Gravitational force goes like $F_g \propto \frac{M}{r^2}$ and the tidal force thus as $F_t \propto \frac{M}{r^3}$. For a moon and its planet the mutual distance is the same. And as the planet has ...