In rare events, the sheath of electrons and ions enveloping Venus in a height of 150 to 300 kilometres can expand into space like a tail. This exceptional deformation occurs on the planet’s night side, when the solar wind, the flow of charged particles from the Sun, nearly comes to a stop. Scientists under the lead of the Max Planck Institute for Solar System Research (MPS) were now for the first time able to study such an event in detail. Their analysis is based on data obtained by instruments on board ESA's spacecraft Venus Express. The results may help to understand, whether particles in our solar system can travel from one planet to another – for example from Venus to Earth.