Magnetopause

The magnetopause is the boundary between a magnetosphere and the surrounding plasma. For planets in the solar system the surrounding plasma is the solar wind emitted by the sun. It behaves roughly like a droplet of liquid exposed to supersonic flow. It is common for the magnetopause to ripple, flap and even to have large droplets break off in the wake of a planet.

See also heliopause, magnetosphere and solar system.