A special ‘Question Time' edition of the programme, recorded at the Civic Theatre, Chelmsford, as part of the British Science Association's annual science festival.
Planetary scientist Dr Carly Howett and cosmologist Professor Hiranya Peiris join Chris Lintott, Maggie Aderin-Pocock and Pete Lawrence to answer questions from viewers covering all things astronomical – from the size of the universe to the possible nature of alien life.
Chaired by Dallas Campbell.