Expected insights on Mercury's interior from the BepiColombo Laser Altimeter
Abstract
We simulate data of the BepiColombo Laser Altimeter (BELA) and investigate the retrieval accuracy for two parameters which pose constraints on Mercury's internal structure: the tidal Love number h2 and the amplitude of Mercury's 88-day libration. Periodic radial displacements of the surface due to solar tides have an amplitude of approximately 2 m at the equator. Mercury's eccentric orbit and non-spherical shape cause its solid shell to librate at orbital frequency with an amplitude of approximately 39 arcsec, equivalent to approximately 460 m at the equator. Both of these signals are contained in the laser altimetry data. In this study, we extract h2 and the libration amplitude along with the global topography, parametrized as an expansion in 2D cubic B-spline basis functions. We show that a tighter constraint on the size of Mercury's liquid core and a detection of the inner solid core will be feasible.
- Publication:
-
EPSC-DPS Joint Meeting 2019
- Pub Date:
- September 2019
- Bibcode:
- 2019EPSC...13...65T