The lecture was delivered by the world-renowned astronomer, Professor Dame Jocelyn Bell Burnell. As well as famously discovering pulsars in the 1960s, Bell Burnell is also known for officiating at the International Astronomical Union in 2006 that decided on a new definition of a planet.

Professor Bell Burnell explained that while the "demotion" of Pluto as a result of that meeting may have been controversial, there was very good reason to do it. As telescopes got bigger and better, more and more objects were being found in the Solar System. If astronomers kept the old definition of a planet, our planet list would be much longer than nine planets, and would include other objects such as Sedna, Makemake, Quaoar, and Eris (which is even bigger than Pluto!).

So many people were looking forward to this year's Christmas Lecture for months, and we were honoured to meet such an esteemed and influential astronomer.

A full report and photos of the event are available HERE.