Liz Bonnin presents a Horizon special about a rare and beautiful event in our solar system that we should all be able to see for ourselves - the transit of Venus across the face of the sun. It will start just after 11pm of the 5th of June 2012 - and won't happen again for more than a century. Joined by scientific specialists from across a wide range of specialisms, Liz explores the history and significance of this rare event as well as revealing how Venus itself has transformed our understanding of life on Earth - and the possibility of life beyond it
