This is an animation of Venus Express performing stellar occultation at Venus.
Venus Express is the first mission ever to apply the technique of stellar occultation at Venus. The technique consists of looking at a star through the atmospheric limb. By analysing the way the starlight is absorbed by the atmosphere, one can deduce the characteristics of the atmosphere itself.
An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a six-month journey, and has been investigating the planet since early 2004.