Check out all the photos from today over on our Facebook page. We'll post all our professional photographer's shots in the next couple of weeks, so watch this space! 

Fans meet John Mason, Patrick Moore and Brian May at today's book signing event.

* Ninian Boyle has copies of his book available to sign via The Widescreen Centre stand

* Dr Paul Brekke will never be far from the Springer stand to sign his latest book 'Our Explosive Sun'

* Dr Simon Singh will be signing his books in the Conference Hall after his talk 'The Big Bang for Beginners' before lunch

* Sir Patrick Moore & Dr John Mason MBE will be signing copies of Patrick Moore's Yearbook of Astronomy 2012 (50th anniversary edition) upstairs in our book signing zone at lunchtime

* Dr Brian May will be signing is OWLs and Astrocards upstairs in the book signing zone at lunchtime 

NASA Goddard Space Flight Center's lunar expert Noah Petro on stage to deliver a fantastic talk on the Moon's biggest impact basins. Noah will be back on stage tomorrow to about the Apollo missions, including more impressive imagery from the Lunar Reconnaissance Orbiter.