spacecraft, launched on August 3, 2004, was inserted in a highly elliptical polar orbit around
the planet on March 18, 2011. One of the main mission goals is the determination of the
interior structure of the planet, enabled by a suite of instruments that includes the radio
system and a laser altimeter. Thanks to altimetric and radio observables, the topography and
the gravity field of the planet have been retrieved with good accuracy, especially in the north …