Constraints set on porosity p and grains size R by the observed thermal inertias of region R₁ of the trailing face of Mimas (dark gray, Γ₁ ≤ 16J/m²/ K/s^1/2) and region R₂ of the leading face (light gray, Γ₂ = 66 ± 23J/m²/ K/s^1/2) of Mimas (Howett et al. 2011). Left panels: crystalline water ice. Right panels: amorphous water ice. Both tight (top panels) and loose (bottom panels) contacts cases are considered too (see Fig. 5 for details). Temperature is assumed to be 80 K here.