Thermal Evolution for the Moon.

(left: Temperature; right: Composition)

In this model, C=0.15 and Hic/Hb=20; Ri = 200 km; Ric = 560 km; T-dependent viscosity with minimum viscosity 1e19 Pas and activation energy 150 KJ/mol; The first phase of instability happens within the IC at about 320 Ma with maximum T of 1682 C. The second phase of instability with longer wavelength happens at about 400 Ma with max T of 1712 C. Thermal expansivity for the liquid phase is 8x10^-5 /K; density difference for the liquid ilmenite is reduced by half.