Thickness of the crust of Mercury from geoid-to-topography ratios

S. Padovan (1) , M. A. Wieczorek (1) , J. -L. Margot , S. C. Solomon

1 IPGP - Institut de Physique du Globe de Paris

From the gravity and topography fields of Mercury determined by the MESSENGER spacecraft, we calculate geoid-to-topography ratios (GTRs) as a means to constrain the average thickness of Mercury's crust. We assume Airy isostasy and exclude regions that might not satisfy this assumption, such as smooth plains and large impact basins. We limit our analysis to spherical harmonic degree n ≥ 5, since lower degrees might be affected by other processes. In the analyzed regions we find that the GTR is 20±4 m/km (1-σ). For an assumed crustal density of 2900 kg m-3, we infer an average crustal thickness of 79±20 km.

Domaines: Planète et Univers [physics]

S. Padovan, M. A. Wieczorek, J. -L. Margot, S. C. Solomon. Thickness of the crust of Mercury from geoid-to-topography ratios. European Planetary Science Congress 2014, 2014, à renseigner, Unknown Region. pp. 1441-1451. ⟨insu-03581137⟩