Margaret G. Kivelson
The 2019 Jean Dominique Cassini Medal & Honorary Membership is awarded to Margaret G. Kivelson for pioneering work in using magnetic fields to understand the interiors of planets and moons, which has revolutionised our vision of them as habitable worlds.
Margaret Kivelson receives the Jean Dominique Cassini medal for her pioneering spacecraft-based investigations of magnetospheric plasmas to determine the natures of the interiors of planets and their moons. Kivelson led the team that discovered an ocean inside Jupiter’s moon Europa and a magnetic field generated by the solar system’s largest moon Ganymede, demonstrating that these moons have active interiors and potentially habitable environments. Her use of magnetometry to infer the presence of oceans has led to the recognition that habitable environments occur beyond the realm of the traditional habitable zone defined by the stability of liquid water on planetary surfaces. As a direct result of Kivelson’s work, we now recognise that the ocean worlds may represent our best chances for discovering life elsewhere in the solar system. Her work has also led to the realisation that many more planets and moons in the cosmos might host life than previously assumed. In doing so, she has revolutionised our vision of planets and moons as habitable worlds.