co-chairs:      D. Smith (David.E.Smith@nasa.gov)
                G. Balmino (balmino@pontos.cst.cnes.fr)

Recent planetary orbiters and probes are providing a wealth of new data about the planets, their orbits, and their dynamics; and several new planetary missions will extend these observations to other bodies. The gravity fields of these bodies are a manifestation of their internal structure that, along with other remote sensing data, can tell us a great deal about the past history of the body. In addition, the tracking observations of the spacecraft not only provide data on the planet and its gravity field and other forces but also about the planet's rotation and its motion around the sun. For this session we encourage the presentation of papers, both oral and poster, on all subjects related to the gravity fields of planets, natural satellites, and asteroidal bodies, all aspects of planetary orbit determination, including spacecraft, and celestial mechanics, ephemeris generation, planetary rotation and dynamics, and the development of planetary topographic and shape models.