It is not just the Earth that has a magnetic field and therefore a magnetosphere. Other planets have magnetospheric cavities due to an internal field which interacts with the solar wind. These are Jupiter, Saturn, Uranus, Neptune and Mercury.
Of particular interest to the group at MSSL is the comparison between the large, rapidly rotating magnetospheres of the gas giants and that of Earth where interaction with the solar wind dominates.
We are also studying objects with no magnetic field and how they interact with the solar wind. These include Mars, Venus and comets.