Animation of Venus, a planet with no magnetic shelter

Differently from Earth, Venus does not have an intrinsic magnetic field to protect it from the solar wind, the constant flow of charged particles generated by the Sun. The planet is only embedded in a local magnetic field induced by the solar wind itself, and perhaps by local magnetism generated by the surface. This peculiar situation gives birth to a complex set of mechanisms by which atmospheric gases are lost to space, including water vapour. Venus Express will study the atmospheric escape processes at Venus and will help understand why the global climate of the planet and its atmopshere evolved in a way so radically different from Earth.