Evolution of the Ancient Lunar Crust Thickness Estimation from the Admittance

We calculate the admittance signatures from the ratio of the gravity and topography data in spectral domain for the four lunar mare basin (Smythii, Crisium, Imbrium, Orientale), which of them have different age. A multitaper method is used to compute the admittance, then compared the observed admittance with the theory values from the model of the lithosphere flexure. on the basis of this method, we obtained the elastic thickness for the four mare basin. The thickness of them is averaged about 8 km to support the observed topography since the time of the loading. The upper crust thickness becoming thick when the evolution wheel of the moon goes ahead. These results are consistent with thermal history of this planets.