Episode Stardate: Mysteries of Venus – As the Venus Express spacecraft approaches its destination this documentary examines this most intriguing of planets and help find the answers to why a planet the same size, age and of similar composition to Earth has become our almost exact opposite. Why is it so hot? Could Venus’s runaway greenhouse effect one day happen on Earth? Why does the entire surface of the planet seem to have been resurfaced in one go? And do the opaque clouds which surround Venus host an even greater mystery: alien life? Presenter Adam Hart-Davis reports from a tense mission control in Germany as the spacecraft is manouvered into orbit. He also takes a quick “holiday” to the surface of Venusas Dr Janet Sumner, a volcanologist from the Open University, replicates Venusian conditions in the lab on Earth: crushing atmospheric pressure 90 times that of Earth, temperature 200 degrees centigrade hotter than a domestic oven, and corrosive clouds of sulphuric acid. Janet also visits the barren volcanic island of Lanzarote, resurfaced in a similar fashion to Venus, but only 300 years ago, and Myleene Klass, musician and Open University astronomy student, shows how you can see Venus for yourself. Dr David Rothery, volcanologist and Chair of the Open University’s planetary science courses explains why the study of Venus is so important, “At the birth of the Solar Systemthere was very little difference between Venus and the Earth. Their size, mass and density are all quite close yet Venus has evolved in an entirely different way. Venus lost its water, but retained a dense carbon dioxide atmosphere. On Earth the carbon dioxide dramatically reduced with the development of life. Unlike Earth, because there is no water, there is no plate tectonics and only sporadic volcanic activity. This may mean that the heat inside the planet is trapped until catastrophic eruptions resurface the whole planet in one go every half billion years or so.