Planetary Reorientation

Planetary bodies can undergo reorientation due to mass redistribution associated with internal or external processes such as convection or impacts. Mass redistribution produces perturbations to the inertia tensor, and the planet must reorient to adjust to the new orientation of the maximum principal axis. The amount of reorientation depends on the competing sizes of the applied load and the remnant bulge. For tidally deformed satellites in synchronous rotation, the slow rotation and correspondingly small remnant bulge makes them prone to reorientation. Reorientation can generate gravity and topography perturbations and large tectonic stresses. Observational constraints based on gravity, tectonic, and paleomagnetic data suggest that many Solar System bodies appear to have undergone significant reorientation.