Special episode of the factual science series exploring the transit of venus across the face of the sun. At 11pm on 5th June 2012 this event will be visible to the naked eye.

Liz Bonnin presents a Horizon special about a rare and beautiful event in our solar system, one that we should all be able to see for ourselves - the transit of Venus across the face of the sun. It will start just before midnight of the 5th of June, and won't happen again for more than a century.

Liz is joined by Lucie Green and Helen Czerski to show why the transit is such a remarkable event - transforming our understanding of our own solar system as well as helping scientists hunt for alien life on distant planets, hundreds of light years away.