Exploring the ocean dynamics of Jupiter’s and Saturn’s icy worlds

Also on Zoom: https://u-paris.zoom.us/j/87804003723?pwd=VjQ1clM4K3ZFY1lKWE5NVHlybFV5QT09 Meeting ID: 878 0400 3723 Passcode: 829548 The subsurface oceans of Jupiter and Saturn's icy moons, such as Europa, Ganymede, Enceladus, and Titan, have long been primary targets in the search for extraterrestrial life. These satellites contain more than water: non-aqueous components such as salts and sulfur have been detected on their surfaces. Organic materials have also been identified within plumes emanating from geysers at Enceladus' South pole. This catalog of observations underscores the significant astrobiological potential of these icy satellites, offering scientists a compelling opportunity to explore planetary habitability. To achieve this, a deep understanding of oceanic circulation is crucial, since it governs the transport of heat and matter from the ocean floor to the icy crust and back. In pursuit of this objective, we have recently developed a new numerical setup specifically designed to simulate the hidden oceans of the icy satellites. Our simulations unveil a planetary-scale oceanic circulation, forming elongated currents in the east-west direction. Thanks to a theoretical understanding of these flows, we predict that typical velocities of these oceanic currents vary from a few centimeters per second for Enceladus to approximately one meter per second for Ganymede. In addition, our research shows that Ganymede's oceanic flow generates its own magnetic field, a phenomenon that will be detectable by the magnetometers of the ESA’s JUICE space mission. This discovery opens up the exciting possibility of mapping the oceanic flow on Europa and Ganymede using magnetic data from the upcoming NASA’s Europa Clipper and ESA’s JUICE missions.