For the last 50 years or so, several robotic space missions have visited the space environments of the gas giant worlds, Jupiter and Saturn. The data from these spacecraft (some single flybys, some dedicated orbiters) have advanced our knowledge of these worlds as having rotationally dominated, disc-like magnetospheres. On the other hand, more refined comparisons have highlighted important differences between Jupiter and Saturn as well. For example, the unusual internal magnetic field of Saturn has a magnetic axis of symmetry almost perfectly parallel to the rotation axis of the planet; and the quasi-periodic oscillations observed in Saturn's particle and field environment, by the Cassini spacecraft, have enabled us to formulate a picture of a complex system where energy is being continually transported between putative vortex-like flows in the atmosphere and the oscillating disturbances in the location and thickness of the plasma disc of the outer magnetosphere. In this talk, we look at some of the important discoveries related to the in situ exploration of the magnetospheres of both planets, and briefly look at some of the related science goals of the JUICE (JUpiter ICy moon Explorer) mission, presently en route to the Jovian system.
Professor Nick Achilleos works with the Astrophysics Group within UCL's Department of Physics and Astronomy. We are also part of the UCL Centre for Planetary Sciences. His current research interests broadly cover the magnetospheres and ionospheres of giant planets (Jupiter and Saturn) and how these systems are coupled together. Previously, Nick has been a mission planner for the team who managed the magnetometer instrument onboard the Cassini spacecraft, currently orbiting the planet Saturn — he is also a science co-investigator at present for the JMAG magnetometer team on the JUICE (JUpiter ICy moons Explorer) mission, currently in flight and due for arrival at Jupiter in 2031. Nick has spent time outside academia as a software developer for the company Logica. He is Director of UCL's Centre for Planetary Sciences, and Vice-Dean of Equity, Diversity and Inclusion for UCL's Faculty of Mathematical and Physical Sciences.