| Astrophysics (Index) | About |
The term gravity sounding (or gravitational sounding) is not widely used, but has been used regarding probes of Jupiter and Saturn. As far as I can make out, it means determining details of the gravitational field and through it, the body's interior structure, by precise observation of the flight path of spacecraft passing the planet, either during a flyby or a (likely eccentric) orbit. Such observations were made with Pioneer and Cassini near Saturn and are being made with Juno orbiting Jupiter.