Nominate your most burning questions about the Universe on the Plus magazine website and we will put them to leading experts, including the Astronomer Royal Martin Rees and cosmologist and author John D Barrow. You’ll be able to read and hear their answers on Plus magazine articles and podcasts after this poll closes, and there’ll be six further polls for you to nominate follow-up questions. This project is our contribution to the International Year of Astronomy 2009.