Mars Express radio science experiment
Date: 26 April 2012
Copyright: Royal Observatory of Belgium
As the spacecraft flies over a volcano, it experiences an attraction towards the elevated mass. Mars Express measures these perturbations in the spacecraft's velocity that induce a detectable Doppler shift on the radio signal between the spacecraft and Earth tracking ground stations. These measurements can be translated into high-precision values for subsurface density variations, providing insight into the thermal history of Mars.
Last Update: 1 September 2019