The transit of Mercury, where the closest planet to the Sun passes in front of it from our view here on Earth, on 9th May 2016 streamed live from the Queen Mary University of London Observatory in East London. The transit takes place between 12:12-19:42 BST. More on what's going on and why: https://www.youtube.com/watch?v=Dl_MoEMwrpE
What is happening and why: https://www.youtube.com/watch?v=Dl_MoEMwrpE