"For me Venus holds special fascination because of it many close connections to Earth, and the important role it has played in our changing ideas about the universe and our place in it. It is brightest thing in our night sky, after the full moon, and has long attracted human worship, fear, and calculation. A slightly twin to our planet in size and weight, Venus (as we have learnt recently) is also currently active planet with a churning interior, young surface and continually recycling atmosphere. It is in many ways the most Earth like of other planets and a natural laboratory for studying some of the most crucial environmental tests facing us."