Computed Q factor for rocky planets with mass ranging between 0.1 and 10 Earth masses (a) for a tidal period of 1 day and three iron content values varying between −50 and +50% relative to the reference value, and (b) for the iron content of the Earth and three tidal periods of 1 (square), 10 (triangle) and 100 (diamond) days. Two extreme values are considered for the very-high-pressure rock viscosity (η_VHP): 5 × 10²² Pa s (gray) assuming no viscosity increase relative to the reference Earth lower mantle and 5.10²⁵ Pa.s (black) assuming a factor 1000 increase relative to the reference, i.e. the lower mantle of the Earth. Curve symbols are the same as in Fig. 2.