Abstract
The Venusian geological features are poorly gravity-resolved and the
state of the core is not well constrained, preventing to understand
Venus’ cooling history. The EnVision candidate mission to the ESA’s
Cosmic Vision Programme consists of a low-altitude orbiter to
investigate geological and atmospheric processes. The gravity experiment
aboard this mission aims to determine Venus’ geophysical parameters to
fully characterize its internal structure. By analyzing the
radio-tracking data that will be acquired through daily operations over
six Venusian days (four Earth’s years), we will derive a highly-accurate
gravity field (spatial resolution better than ~170 km),
allowing to detect lateral variations of the lithosphere and crust
properties beneath most of the geological features. The expected 0.3%
error on the Love number k2, 0.1° error on the
tidal phase lag and 1.4% error on the moment of inertia are fundamental
to constrain the core size and state as well as the mantle viscosity.