RESULTS FROM PANEL DISCUSSION SESSION 4: OUTER PLANETS - FUTURE MISSION CONCEPTS AND TECHNOLOGY NEEDS.

The discussion focused on the scientific priorities and technological requirements for the exploration of the outer planets with entry probes. There are two kinds of measurements that appear essential to answer at this time to understand the formation of the Solar System: the bulk abundance of water in Jupiter and other gas giants, and the abundance of noble gases in Saturn, Uranus and Neptune. Our current knowledge about the elemental composition of the Jupiter's atmosphere following the Galileo Entry Probe mission is good. Measurements of the water abundance are expected from the recently selected NASA mission, Juno. Detailed knowledge of the composition of the mixed atmosphere of Saturn as compared to that of Jupiter is fundamental as the next step in constraining models of giant planet formation and the origin of their atmospheres. This emerged as the highest near-term priority in the exploration of the giant planets. This will lead to a better understanding of the formation and evolution of our Solar System and consequently planetary systems around other stars. A dedicated Outer Planet Exploration Programme with an objective to visit all the outer planets was discussed. This programme would include a probe mission every 710 years. International partnership will be vital for such a programme.